New Circuits Page 202
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In this circuit, an NE592 acts as an IF amplifier. DC coupling between mixer and amplifier is practical beacuse different + 6 V and + 12 V supply voltages are used. The voltage at the differential input is about 4.5 V. A narrow bandpass filter for the....
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This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm and lights an LED, but can be interfaced to any number of other circuits for many different uses...
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This circuit can detect the positive peaks for signal frequencies higher than 5 MHz. It yields ±1% accuracy for 400 mV to 4 V pk-pk signal amplitudes on sine, square, and triangular waveforms. The Am685 comparator output increases whenever VrN is a....
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The sample-and-hold function has often been accomplished with separate analog switches and op amps. These designs always involve performance tradeoffs between acquisition time, charge injection, and droop rate. The HA-242-/2425 monolithic....
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Using a capacitor sensor to detect a water level is a simple method of sensing. This circuit uses C5, which..
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When the light beam that falls in the CDS photocell is interrupted, transistor (EN3904) conducts thereby triggering SCR1 (CI06) and activating alarm bell. SI resets the SCR. The alarm bell should be a self-interrupting electromechanical type...
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Transistor Q1, a 2N3563, and its associated components form an oscillator circuit that will oscillate if, and only if, a good crystal is connected to the test clips. The output from the oscillator is then rectified by the 1N4148 signal diode and filtered by....
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Got no dough for a commercial WiFi antenna? Looking for an inexpensive way to increase the range of your wireless network? A tin can waveguide antenna, or Cantenna, may be just the ticket. This design can be built for under $5 U.S. and reuses a food, juice,....
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This circuit will remove the transient spikes and contact bounces from a non-latching push button switch. Using a 555 timer as a monostable circuit, it is easy to build a good switch debouncer circuit. There are many circuits for SPDT debouncing, but not....
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The circuit below uses a CMOS dual D flip flop (CD4013) to toggle a relay or other load with a momentary push button. Several push buttons can be wired in parallel to control the relay from multiple locations. A high level from the push button is coupled to....
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No Description available...
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This circuit is a small digital ?roulette''. It is constituted by oscillator IC1, the counter IC2, the transistors Q1-7 that drive the display common cathode DSP1. The supply basically becomes from a battery 9V, but can become also from one power supply.....
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The charger is based on the LTC4053a standalone
timer-terminated constant current/constant voltage linear
charger. The LTC4053 features a thermal loop which
maximizes the charging rate under all conditions by
regulating the maximum die temperature. Less....
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A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance. This is a 3 stage discrete amplifier with gain control. Alternative transistors such as BC109C, BC548, BC549, BC549C may be used with little change in....
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This project was a particular surprise for me in that the BC547 (equiv 2N2222) can be used to build a 500mW linear amplifer covering the entire HF band with excelent spectral purity and no neutralising at all. Ugly-bug construction was used but I dare say....
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What makes this control unique is its momentum feature, which adds a degree of realism. The circuit will opera..
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This is a gas detecting circuit capable of sensing many different types of gases. The sensor used is the GH-312 and from the datasheet it is capable of sensing gases like smoke, liquefied gas, butane and propane, Methane, alcohol, hydrogen, etc. I've used a....
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This op-amp analyzer can measure the current drawn by any device in a car. The analyzer works by measuring the very small voltage that develops across the battery cables when current flows..
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The circuit utilizes CA3160 and CA3140 BiMOS op amps to provide a full-scale meter deflection of ± 3 pA. The CA3140 serves as an 1T0 gain stage to provide the required plus and minus output swing for the meter and feedback network. ..
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I finally found a very nice universal window based software designed to work with any serial programmers for PIC16F84, i.e., WPicProg16 V1.20, written by Nigel Goodwin. Build this programmer before started experimenting the forthcoming many interesting F84....
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The base of Ql is connected to the car`s ignition circuit; the easiest point to make that connection is at the ignition switch fuse in the car`s fuse panel. Also, one side of the piezoelectric buzzer is connected to the instrument-panel light fuse; when the....
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This kit is the most basic, practical circuit to build using an
LDR to turn on a relay. The two transistors connected as a
Darlington pair give the circuit enough sensitivity, while
the trimpot give sensitivity adjustment. The switching
point of the....
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Our circuit is amplifying the current flowing through your finger (when it touches the touch plate) 10,000 times and this is sufficient to illuminate the LED. The current flowing through your finger (when touching the touch plate) is only a few microamps and....
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The improved system is called RC-CAM2. It works better AND it costs less than my earlier attempt to get a wireless video system on my flying model. The only caveat is that there is some assembly (or disassembly as you will soon find out) required...
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In contrast, the circuit in Figure 1 physically inserts a resistor in series with the load to limit the inrush current and then short-circuits the resistor after a time delay. You can adapt the circuit to any size load by suitably selecting the series....
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The circuit uses a four-bit latch (Ul). What makes the circuit sequential is that the set input of the first bit latch is tied..
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The catering better it does not become at straight line from the network 220V but via transformer 220V/220V of isolation and safety 1A. When does not exist the R3, the force of expense is bigger, but respectively is increased also the hum 50Hz, because the....
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This is a circuit monitoring device. It runs for over 10 days and can log up to 32k events both digital and analog. Samples are logged either on a timing basis (.01 to 2.5 seconds), or on a triggered basis. Four inputs are provided, up to three of which can....
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The two lamp-dimmer circuits differ in that (a) employs a single-time-constant trigger network and (b) uses a double-time-constant trigger circuit that reduces hysteresis effects and thereby extends the effective range of the light-control potentiometer.....
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If a NiCad battery is discharged to a point at which the lowest capacity cell becomes fully discharged and reverses polarity, that cell will usually short internally and become unusable. To prevent this type of damage, this circuit detects a one-cell drop of....
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In applications where the period of the input pulses is uneven and the divider is required to cover a wide range of frequencies, the non-integer programmable pulse divider shown can be used. The purpose of the D-type flip-flop (IC2) is to synchronize the....
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Completed STK465 is an amplifier of acoustic frequencies that offers qualitative output, using minimal exterior elements. Substantially he is one of big completed force. Has a line pins and incorporated metal surface for adaptation in cooler. The provision....
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That circuit will provide an overall gain of one between the output and each input channel. Each input channel includes a single 0.1uf capacitor and 100-Kilohms resistor to provide an output impedance of 100K. The number of input channels to this audio mixer....
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The WWVB signal is broadcast as a 60 kHz carrier that is AM modulated with a time code frame that is updated once per minute. The data rate is one bit per second. Along with time code information, the data frame also contains synchronization bits, calendar....
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The preamplifier was designed to signal sources such as low-impedance moving coil cartridges (MC) on turntables
high fidelity (and yet still there). The impedance of the amplifier is 100 W. To keep the noise levels low, three double-type transistors MAT03....
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The circuit of Figure 1 is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. The circuit drives as many as four white LEDs from a 3.3V source and adjusts the total LED current from 1 to 106 mA in 64....
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It may be easy to find a precision voltage reference for your application; however, a programmable precision reference is another matter. The circuit in Figure 1 yields a precision reference with an LSB of 62.5 µV. The circuit is a 16-bit DAC using three....
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This circuit provides a simple, low-cost crosshatch generator tor convergence and geometry adJUStments on color TVs. The generator is driven by two clocks, one for the horizontal drive, IC1ab, and one for the vertical drive, IC2ab. The clock outputs are....
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The capacitance between the wire and the probe would form a capacitive voltage divider with the probe's input capacitance, and at frequencies significantly higher than the low frequency roll off created by the probe's input capacitance and the probe's....
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Bridge circuit contains two resistors lOO-ohm (R3 and R4), and two thermistors (Tl and T2). At room temperature, the resistance of T1 and 1'2 is about 2000 ohms. When they are each heated to 150 ° C by an RNA 10 current, the resistance value decreases to....
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The logic diagram of the CD4538BC Dual Precision Monostable is shown in the following schematic diagram. This IC such a dual, precision monostable multivibrator with independent trigger and controls, according to the datasheet. This CD4538BC IC features wide....
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When the doorbell switch is pressed, the two monostable stages are activated in sequence, applying bias to a pair of voltage-controlled resistor stages. These then modulate the outputs from a pair of tone generators. The resulting signals are fed to an....
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Most battery motor speed controllers are under manual control and the operator automatically adjusts speed to match demand. Under these conditions closed loop motor speed control is an unnecessary expense. However, when it is required, a tachogenerator can....
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Sometimes, you need to remotely turn on or off a two-state system, such as a light, from multiple points. You could connect simple pushbutton switches in parallel to a single-line bus. However, if the bus simply controls a toggle flip-flop, the system must....
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This is the latest BH1417 FM Transmitter design from RHOM that includes a lot of features in one small package. It comes with pre-emphasis, limiter so that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass....
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A shows a COR/CAS circuit for repeater use. CR1 is a silicon diode. 2 may be any relay with a 12-V coil (a long-life..
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An LT1172 generates positive and negative voltages from a 5-V input. The LT1172 is configure..
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This GAL programmer is controlled via a parallel port, so that any exclusive interface is not requires for the programmer. It is easy to use on the notebook PCs. When program a PIC, a socket converter is needed. After assembly is finished, check if the....
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Although the TDA2030 can deliver 20 watts of output power, I deliberately reduced the output power to about 8 watts to supply 10 watt speakers. Input sensitivity is 200mV. Higher input levels naturally will give greater output, but no distortion should be....
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A line amplifier is always a useful unit to have around, whether it is for matching a line signal or raising..
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Many devices operate from a car"s 12-V electrical system. Some require 12 V; others require some lesser voltage. An automobile battery"s output can vary from 12 to 13.8 V under normal circumstances. The load requirements of the device might vary. This....
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This circuit was used to produce a variable negative voltage for contrast control of an LCD displa..
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The page is about equipping an Atmel AVR microcontroller based system with a Prism WLAN interface. This document is intended for people that already have experiences with the AVR microcontrollers and teaches them how to add a cheap but flexible WLAN....
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When operated as an open loop without compensation, the HA-2400 becomes a comparator with four selectable input channels. The clamping network at the compensation pin limits the output voltage to allow DTLor TTL digital circuits to be driven with a fanout....
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The Vx2SE is a simple discrete voltage-doubling SE for driving an LED. If the load is a red or green LED, J1 is used together with just one red or green LED for threshold detection (no 1381). For driving a blue LED use two green or red LEDs in series and....
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This design was never completely finished, so consider it to be in the very early experimental stage. I don`t sell kits, programmed PLD`s, or provide support for this project, and I will never be published. But if you want to take a bash at making it....
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The circuit has been designed to accommodate all those who dedicate many hours of their lives by exploring the endless pages of this site. Despite the fact that it consists of only three components (Most were not little!), Is able to provide an indication of....
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The LTC®1541 combines a micropower amplifier, comparator
and 1.2V reference in an 8-pin package. The part
operates from a single 2.5V to 12.6V supply with typical
supply current of 5mA. Both op amp and comparator
feature a common mode input voltage range....
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The DMM-ProfiLab-Software allows you to develop any measuring technology projects based upon digital multimeters: A simple curve plotter or a complex measuring technology project. By the integrated support of relay cards you are not only able to read and....
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The input signal drives ICD. Because ICD"s positive input (V+) is slightly offset to + 0.1 V, its steady state ..
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The circuit of the unit is fairly simple, but is a bit irksome to set up. The reason is that obtaining matched FETs is not easy, so I had to make sure that the circuit would work with off-the-shelf FETs.
The phase shifter is a standard opamp circuit, and....
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This has a stable trigger 100 m V sensitivity at 50 MHz. The FETs comprise a simple high-speed buffer and the LT1016 compares the buffer"s output to the potential at tbe trigger level potentiometer, which can be of either polarity. The 10-KO resistor....
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The question sometimes comes up of how to cascade 4017 decade counters for more than 10 sequencial stages. The LED sequencer below shows a possible solution using a few extra parts. When power is applied, the 15K resistor and 10uF cap at pin 15 will reset....
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Just point this small device at the TV and the remote gets jammed . The circuit is self explanatory . 555 is wired as an astable multivibrator for a frequency of nearly 38 kHz. This is the frequency at which most of the modern TVs receive the IR beam . The....
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This circuit combines the characteristics of an asynchronous S/R flip-flop and an edge-triggered JK flip-flop. It changes sta..
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The basic idea comes from the AN592 Microchip application note: "Frequency counter using
PIC16C5x". where you may find a simple software wich implements a frequency counter using a
PIC microcontroller.I wrote a specifically designed software to improve....
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The machine model, commonly used for ESD testing in Japan, is a more severe ESD test. This model simulates metallic contact between the device under test and a charged body. The source capacitor is 200pF with no limiting resistor. The higher source....
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This circuit draws only 4 mA from a 5-V supply while driving a standard RS-232C receiver. The system clock drives a de-de converter that produces -3.4 V. The frequency can range from 0.5 to 8 MHz, but a range of 0.5 to 1 MHz will minimize power....
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Itis often required that a signal be filtered prior to sampling. This can be accomplished with only one device. Use any of the inverting and noninverting filters that can be built with op amps. ..
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This interface is needed to connect the phone to a PC, because the PC`s serial port works with voltage levels between -12 and 12V (RS232 protocol) and the phone operates between 0 and 5V (TTL protocol). Don`t even think in conecting your phone directly to....
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The demonstration circuit operates in the HM2007's manual mode. This mode uses a simple keypad and digital display to communicate with and program the HM2007 chip. When the circuit is turned on, the HM2007 checks the static RAM. If everything checks out the....
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This circuit holds on the internal light for approximately one minute after the car doors are closed. When the door contacts open, a + VE pulse is applied to the base of Tl. This transistor turns on, turning off T2 and charging the 10-llF capacitor. T3....
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ICl is a 555 timer running at about 16 kHz. This IC drives Ql, a TIP146, which produces a 12-V square wave across Tl pri..
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Electrical potentials are generated by muscle when there is movement. This Signal can be pick up by electrode to form EMG. For my Final Year Project, I did an amplifier and signal conditioning circuit for EMG. Attached below is the schematics for the....
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This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some....
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The difficulty of connection vga of a videocard to the TV set is, that Frequency of lower case development(display) of the TV set makes 15 KHz, and VGA card - from 31 KHz and is higher. Translation of development(display) of the TV set up to 31 KHz....
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The heart of the circuit is the tone (pitch) display section, based on the popular LM3914 display driver. This device drives ten LEDs in a linear display, with programmable endpoints and the choice of "dot" or "bar" modes of operation. Furthermore, it is....
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his Electronic Lock circuit is not only simple but it is also very good. It can easily be configured to provide either momentary or continuous output. Key sequences of up to 9 digits are possible. You can pre-enter part of the combination and then have....
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The 741 has a maximum gain of 20,000, but the circuit is so designed that the IC"s gain is 2,700,000 which then distorts the output. This distortion gives the fuzz effect. The two diodes clip the output to drop the level, also lowered by the potential divider..
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The CD4069 or 74C04 hex inverter—is used as^ fixed-frequency oscillator centered around 100 kHz. U2 contains the variable frequency oscillator and balanced modulator. The CD4046 is a phase-locked loop and R3, R4, and C2 determine the center frequency of....
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The circuit provides a 10MHz cutoff frequency. Resistor R3 ensures that the input capacitance of the amplifier does not interact with the filter response at the frequency of interest. ..
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This circuit performs the function of dividing the input signal by a selected constant (1, 2, 4, 8, etc.). While T, Z, or L sections could be used in the input attenuator, this is not necessary since the amplifier loading is negligible and a constant input....
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By adjusting one potentiometer, this circuit`s output can be varied from a positive-going version of the input signal, smoothly through zero output, then to a negative-going version of the input (see the figure). If the input signal is a positive pulse of,....
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This 0- to 12-Vdc variable power supply uses an IC voltage regulator and a heavy-duty transformer to provide a reliable dc power supply. Looking at the schematic shown, you can sec that transformer Tl has a 120-V primary and a 28-V secondary. Filtered dc is....
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Dew (condensed moisture) ad- versely affects the normal per- formance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an....
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This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight. A Rotary Switch sets the timer according to six classified Photo-types (see table). A Photo resistor extends the preset time....
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It was designed for an application in a welding machine: there are lots of bits of machinery which are cylindrical in shape and which are subjected to heavy surface wear. For instance ore crushers, and the idler and roller wheels off track laying vehicles,....
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PicCon is a PIC microcontroller based radio controller designed for hidden transmitter hunting. When combined with a radio transmitter, it will produce tone sequences and Morse code messages at user-programmed times. It is completely field programmable via....
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Often the need to control light switch on the instrument. If napájíme LED source of low DC voltage sufficient to classify a series of LED-resistor of appropriate resistance. Another situation occurs, if a small supply available, or to indicate when the....
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The design usually involves a compromise between turn-on voltage and lamp life because the two are inversely related. One way to reach a reasonable compromise is to initially allow a momentary inrush current to warm the filaments, followed by a series of....
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The controller circuit can reduce a fan"s noise, power consumption, and wear, particularly in the presence of a low, fluctuating ambient temperature. Mount a temperature sensor in the fan"s airstream, and the circuit will adjust the fan speed as necessary....
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A very good circuit of pre-preamplifier, for amplification of signals from heads of Moving Coil. It uses the two departments of tube ECC88, association parallel, for reduction of produced noise. The circuit enters in line with existing circuit PHONO.....
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When this circuit is connected to a filter and an oscilloscope, the scope displays the filter"s frequency response. A..
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The pseudorandom sequencer drives a solid-state relay. If you power a low-wattage lamp from the re..
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RF Power Amplifier 1 Watt. Jams Cellular Downlink Band: 800-950 MHz...
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A variable oscillator covers 3.2 to 22 MHz in two bands—providing coverage of 80 through 15 meters plus most crystal-filter frequencies. Optional 455 kHz and 10.7 MHz crystal oscillators can be switched on-line for precise if alignment. Generator output is....
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Mains frequency is pretty stable and it is unlikely that you have to measure it but if you have an emergency generator you might find this circuit useful as it will give an indication whether the generator is running too fast or too slow. Actually you can....
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The shift pulse amplitude is less than 15 volts. If a stage is off, the shift pulse will not be coupled to the next stage. If it is on, the diode will conduct and trigger the next stage. Just prior to the shift pulse the anode supply is interrupted to tum....
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This is an image Schematic. No Description available...
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This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively....
In this circuit, an NE592 acts as an IF amplifier. DC coupling between mixer and amplifier is practical beacuse different + 6 V and + 12 V supply voltages are used. The voltage at the differential input is about 4.5 V. A narrow bandpass filter for the....
This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm and lights an LED, but can be interfaced to any number of other circuits for many different uses...
This circuit can detect the positive peaks for signal frequencies higher than 5 MHz. It yields ±1% accuracy for 400 mV to 4 V pk-pk signal amplitudes on sine, square, and triangular waveforms. The Am685 comparator output increases whenever VrN is a....
The sample-and-hold function has often been accomplished with separate analog switches and op amps. These designs always involve performance tradeoffs between acquisition time, charge injection, and droop rate. The HA-242-/2425 monolithic....
Using a capacitor sensor to detect a water level is a simple method of sensing. This circuit uses C5, which..
When the light beam that falls in the CDS photocell is interrupted, transistor (EN3904) conducts thereby triggering SCR1 (CI06) and activating alarm bell. SI resets the SCR. The alarm bell should be a self-interrupting electromechanical type...
Transistor Q1, a 2N3563, and its associated components form an oscillator circuit that will oscillate if, and only if, a good crystal is connected to the test clips. The output from the oscillator is then rectified by the 1N4148 signal diode and filtered by....
Got no dough for a commercial WiFi antenna? Looking for an inexpensive way to increase the range of your wireless network? A tin can waveguide antenna, or Cantenna, may be just the ticket. This design can be built for under $5 U.S. and reuses a food, juice,....
This circuit will remove the transient spikes and contact bounces from a non-latching push button switch. Using a 555 timer as a monostable circuit, it is easy to build a good switch debouncer circuit. There are many circuits for SPDT debouncing, but not....
The circuit below uses a CMOS dual D flip flop (CD4013) to toggle a relay or other load with a momentary push button. Several push buttons can be wired in parallel to control the relay from multiple locations. A high level from the push button is coupled to....
This circuit is a small digital ?roulette''. It is constituted by oscillator IC1, the counter IC2, the transistors Q1-7 that drive the display common cathode DSP1. The supply basically becomes from a battery 9V, but can become also from one power supply.....
The charger is based on the LTC4053a standalone timer-terminated constant current/constant voltage linear charger. The LTC4053 features a thermal loop which maximizes the charging rate under all conditions by regulating the maximum die temperature. Less....
A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance. This is a 3 stage discrete amplifier with gain control. Alternative transistors such as BC109C, BC548, BC549, BC549C may be used with little change in....
This project was a particular surprise for me in that the BC547 (equiv 2N2222) can be used to build a 500mW linear amplifer covering the entire HF band with excelent spectral purity and no neutralising at all. Ugly-bug construction was used but I dare say....
What makes this control unique is its momentum feature, which adds a degree of realism. The circuit will opera..
This is a gas detecting circuit capable of sensing many different types of gases. The sensor used is the GH-312 and from the datasheet it is capable of sensing gases like smoke, liquefied gas, butane and propane, Methane, alcohol, hydrogen, etc. I've used a....
This op-amp analyzer can measure the current drawn by any device in a car. The analyzer works by measuring the very small voltage that develops across the battery cables when current flows..
The circuit utilizes CA3160 and CA3140 BiMOS op amps to provide a full-scale meter deflection of ± 3 pA. The CA3140 serves as an 1T0 gain stage to provide the required plus and minus output swing for the meter and feedback network. ..
I finally found a very nice universal window based software designed to work with any serial programmers for PIC16F84, i.e., WPicProg16 V1.20, written by Nigel Goodwin. Build this programmer before started experimenting the forthcoming many interesting F84....
The base of Ql is connected to the car`s ignition circuit; the easiest point to make that connection is at the ignition switch fuse in the car`s fuse panel. Also, one side of the piezoelectric buzzer is connected to the instrument-panel light fuse; when the....
This kit is the most basic, practical circuit to build using an LDR to turn on a relay. The two transistors connected as a Darlington pair give the circuit enough sensitivity, while the trimpot give sensitivity adjustment. The switching point of the....
Our circuit is amplifying the current flowing through your finger (when it touches the touch plate) 10,000 times and this is sufficient to illuminate the LED. The current flowing through your finger (when touching the touch plate) is only a few microamps and....
The improved system is called RC-CAM2. It works better AND it costs less than my earlier attempt to get a wireless video system on my flying model. The only caveat is that there is some assembly (or disassembly as you will soon find out) required...
The circuit uses a four-bit latch (Ul). What makes the circuit sequential is that the set input of the first bit latch is tied..
The catering better it does not become at straight line from the network 220V but via transformer 220V/220V of isolation and safety 1A. When does not exist the R3, the force of expense is bigger, but respectively is increased also the hum 50Hz, because the....
This is a circuit monitoring device. It runs for over 10 days and can log up to 32k events both digital and analog. Samples are logged either on a timing basis (.01 to 2.5 seconds), or on a triggered basis. Four inputs are provided, up to three of which can....
The two lamp-dimmer circuits differ in that (a) employs a single-time-constant trigger network and (b) uses a double-time-constant trigger circuit that reduces hysteresis effects and thereby extends the effective range of the light-control potentiometer.....
If a NiCad battery is discharged to a point at which the lowest capacity cell becomes fully discharged and reverses polarity, that cell will usually short internally and become unusable. To prevent this type of damage, this circuit detects a one-cell drop of....
In applications where the period of the input pulses is uneven and the divider is required to cover a wide range of frequencies, the non-integer programmable pulse divider shown can be used. The purpose of the D-type flip-flop (IC2) is to synchronize the....
Completed STK465 is an amplifier of acoustic frequencies that offers qualitative output, using minimal exterior elements. Substantially he is one of big completed force. Has a line pins and incorporated metal surface for adaptation in cooler. The provision....
That circuit will provide an overall gain of one between the output and each input channel. Each input channel includes a single 0.1uf capacitor and 100-Kilohms resistor to provide an output impedance of 100K. The number of input channels to this audio mixer....
The WWVB signal is broadcast as a 60 kHz carrier that is AM modulated with a time code frame that is updated once per minute. The data rate is one bit per second. Along with time code information, the data frame also contains synchronization bits, calendar....
The preamplifier was designed to signal sources such as low-impedance moving coil cartridges (MC) on turntables high fidelity (and yet still there). The impedance of the amplifier is 100 W. To keep the noise levels low, three double-type transistors MAT03....
It may be easy to find a precision voltage reference for your application; however, a programmable precision reference is another matter. The circuit in Figure 1 yields a precision reference with an LSB of 62.5 µV. The circuit is a 16-bit DAC using three....
This circuit provides a simple, low-cost crosshatch generator tor convergence and geometry adJUStments on color TVs. The generator is driven by two clocks, one for the horizontal drive, IC1ab, and one for the vertical drive, IC2ab. The clock outputs are....
The capacitance between the wire and the probe would form a capacitive voltage divider with the probe's input capacitance, and at frequencies significantly higher than the low frequency roll off created by the probe's input capacitance and the probe's....
Bridge circuit contains two resistors lOO-ohm (R3 and R4), and two thermistors (Tl and T2). At room temperature, the resistance of T1 and 1'2 is about 2000 ohms. When they are each heated to 150 ° C by an RNA 10 current, the resistance value decreases to....
The logic diagram of the CD4538BC Dual Precision Monostable is shown in the following schematic diagram. This IC such a dual, precision monostable multivibrator with independent trigger and controls, according to the datasheet. This CD4538BC IC features wide....
When the doorbell switch is pressed, the two monostable stages are activated in sequence, applying bias to a pair of voltage-controlled resistor stages. These then modulate the outputs from a pair of tone generators. The resulting signals are fed to an....
Most battery motor speed controllers are under manual control and the operator automatically adjusts speed to match demand. Under these conditions closed loop motor speed control is an unnecessary expense. However, when it is required, a tachogenerator can....
This is the latest BH1417 FM Transmitter design from RHOM that includes a lot of features in one small package. It comes with pre-emphasis, limiter so that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass....
A shows a COR/CAS circuit for repeater use. CR1 is a silicon diode. 2 may be any relay with a 12-V coil (a long-life..
An LT1172 generates positive and negative voltages from a 5-V input. The LT1172 is configure..
This GAL programmer is controlled via a parallel port, so that any exclusive interface is not requires for the programmer. It is easy to use on the notebook PCs. When program a PIC, a socket converter is needed. After assembly is finished, check if the....
Although the TDA2030 can deliver 20 watts of output power, I deliberately reduced the output power to about 8 watts to supply 10 watt speakers. Input sensitivity is 200mV. Higher input levels naturally will give greater output, but no distortion should be....
A line amplifier is always a useful unit to have around, whether it is for matching a line signal or raising..
Many devices operate from a car"s 12-V electrical system. Some require 12 V; others require some lesser voltage. An automobile battery"s output can vary from 12 to 13.8 V under normal circumstances. The load requirements of the device might vary. This....
This circuit was used to produce a variable negative voltage for contrast control of an LCD displa..
The page is about equipping an Atmel AVR microcontroller based system with a Prism WLAN interface. This document is intended for people that already have experiences with the AVR microcontrollers and teaches them how to add a cheap but flexible WLAN....
When operated as an open loop without compensation, the HA-2400 becomes a comparator with four selectable input channels. The clamping network at the compensation pin limits the output voltage to allow DTLor TTL digital circuits to be driven with a fanout....
The Vx2SE is a simple discrete voltage-doubling SE for driving an LED. If the load is a red or green LED, J1 is used together with just one red or green LED for threshold detection (no 1381). For driving a blue LED use two green or red LEDs in series and....
This design was never completely finished, so consider it to be in the very early experimental stage. I don`t sell kits, programmed PLD`s, or provide support for this project, and I will never be published. But if you want to take a bash at making it....
The circuit has been designed to accommodate all those who dedicate many hours of their lives by exploring the endless pages of this site. Despite the fact that it consists of only three components (Most were not little!), Is able to provide an indication of....
The DMM-ProfiLab-Software allows you to develop any measuring technology projects based upon digital multimeters: A simple curve plotter or a complex measuring technology project. By the integrated support of relay cards you are not only able to read and....
The input signal drives ICD. Because ICD"s positive input (V+) is slightly offset to + 0.1 V, its steady state ..
The circuit of the unit is fairly simple, but is a bit irksome to set up. The reason is that obtaining matched FETs is not easy, so I had to make sure that the circuit would work with off-the-shelf FETs. The phase shifter is a standard opamp circuit, and....
This has a stable trigger 100 m V sensitivity at 50 MHz. The FETs comprise a simple high-speed buffer and the LT1016 compares the buffer"s output to the potential at tbe trigger level potentiometer, which can be of either polarity. The 10-KO resistor....
The question sometimes comes up of how to cascade 4017 decade counters for more than 10 sequencial stages. The LED sequencer below shows a possible solution using a few extra parts. When power is applied, the 15K resistor and 10uF cap at pin 15 will reset....
Just point this small device at the TV and the remote gets jammed . The circuit is self explanatory . 555 is wired as an astable multivibrator for a frequency of nearly 38 kHz. This is the frequency at which most of the modern TVs receive the IR beam . The....
This circuit combines the characteristics of an asynchronous S/R flip-flop and an edge-triggered JK flip-flop. It changes sta..
The basic idea comes from the AN592 Microchip application note: "Frequency counter using PIC16C5x". where you may find a simple software wich implements a frequency counter using a PIC microcontroller.I wrote a specifically designed software to improve....
The machine model, commonly used for ESD testing in Japan, is a more severe ESD test. This model simulates metallic contact between the device under test and a charged body. The source capacitor is 200pF with no limiting resistor. The higher source....
This circuit draws only 4 mA from a 5-V supply while driving a standard RS-232C receiver. The system clock drives a de-de converter that produces -3.4 V. The frequency can range from 0.5 to 8 MHz, but a range of 0.5 to 1 MHz will minimize power....
Itis often required that a signal be filtered prior to sampling. This can be accomplished with only one device. Use any of the inverting and noninverting filters that can be built with op amps. ..
This interface is needed to connect the phone to a PC, because the PC`s serial port works with voltage levels between -12 and 12V (RS232 protocol) and the phone operates between 0 and 5V (TTL protocol). Don`t even think in conecting your phone directly to....
The demonstration circuit operates in the HM2007's manual mode. This mode uses a simple keypad and digital display to communicate with and program the HM2007 chip. When the circuit is turned on, the HM2007 checks the static RAM. If everything checks out the....
This circuit holds on the internal light for approximately one minute after the car doors are closed. When the door contacts open, a + VE pulse is applied to the base of Tl. This transistor turns on, turning off T2 and charging the 10-llF capacitor. T3....
ICl is a 555 timer running at about 16 kHz. This IC drives Ql, a TIP146, which produces a 12-V square wave across Tl pri..
Electrical potentials are generated by muscle when there is movement. This Signal can be pick up by electrode to form EMG. For my Final Year Project, I did an amplifier and signal conditioning circuit for EMG. Attached below is the schematics for the....
This is a project that I started back late 2003 when I just starting to learn PIC programming. I wanted to building something that actually did somthing useful. This project is based on a PIC16F84. I actually came up with this idea and then after doing some....
The difficulty of connection vga of a videocard to the TV set is, that Frequency of lower case development(display) of the TV set makes 15 KHz, and VGA card - from 31 KHz and is higher. Translation of development(display) of the TV set up to 31 KHz....
The heart of the circuit is the tone (pitch) display section, based on the popular LM3914 display driver. This device drives ten LEDs in a linear display, with programmable endpoints and the choice of "dot" or "bar" modes of operation. Furthermore, it is....
his Electronic Lock circuit is not only simple but it is also very good. It can easily be configured to provide either momentary or continuous output. Key sequences of up to 9 digits are possible. You can pre-enter part of the combination and then have....
The 741 has a maximum gain of 20,000, but the circuit is so designed that the IC"s gain is 2,700,000 which then distorts the output. This distortion gives the fuzz effect. The two diodes clip the output to drop the level, also lowered by the potential divider..
The CD4069 or 74C04 hex inverter—is used as^ fixed-frequency oscillator centered around 100 kHz. U2 contains the variable frequency oscillator and balanced modulator. The CD4046 is a phase-locked loop and R3, R4, and C2 determine the center frequency of....
The circuit provides a 10MHz cutoff frequency. Resistor R3 ensures that the input capacitance of the amplifier does not interact with the filter response at the frequency of interest. ..
This circuit performs the function of dividing the input signal by a selected constant (1, 2, 4, 8, etc.). While T, Z, or L sections could be used in the input attenuator, this is not necessary since the amplifier loading is negligible and a constant input....
By adjusting one potentiometer, this circuit`s output can be varied from a positive-going version of the input signal, smoothly through zero output, then to a negative-going version of the input (see the figure). If the input signal is a positive pulse of,....
This 0- to 12-Vdc variable power supply uses an IC voltage regulator and a heavy-duty transformer to provide a reliable dc power supply. Looking at the schematic shown, you can sec that transformer Tl has a 120-V primary and a 28-V secondary. Filtered dc is....
Dew (condensed moisture) ad- versely affects the normal per- formance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an....
This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight. A Rotary Switch sets the timer according to six classified Photo-types (see table). A Photo resistor extends the preset time....
It was designed for an application in a welding machine: there are lots of bits of machinery which are cylindrical in shape and which are subjected to heavy surface wear. For instance ore crushers, and the idler and roller wheels off track laying vehicles,....
PicCon is a PIC microcontroller based radio controller designed for hidden transmitter hunting. When combined with a radio transmitter, it will produce tone sequences and Morse code messages at user-programmed times. It is completely field programmable via....
Often the need to control light switch on the instrument. If napájíme LED source of low DC voltage sufficient to classify a series of LED-resistor of appropriate resistance. Another situation occurs, if a small supply available, or to indicate when the....
The controller circuit can reduce a fan"s noise, power consumption, and wear, particularly in the presence of a low, fluctuating ambient temperature. Mount a temperature sensor in the fan"s airstream, and the circuit will adjust the fan speed as necessary....
A very good circuit of pre-preamplifier, for amplification of signals from heads of Moving Coil. It uses the two departments of tube ECC88, association parallel, for reduction of produced noise. The circuit enters in line with existing circuit PHONO.....
When this circuit is connected to a filter and an oscilloscope, the scope displays the filter"s frequency response. A..
The pseudorandom sequencer drives a solid-state relay. If you power a low-wattage lamp from the re..
RF Power Amplifier 1 Watt. Jams Cellular Downlink Band: 800-950 MHz...
A variable oscillator covers 3.2 to 22 MHz in two bands—providing coverage of 80 through 15 meters plus most crystal-filter frequencies. Optional 455 kHz and 10.7 MHz crystal oscillators can be switched on-line for precise if alignment. Generator output is....
Mains frequency is pretty stable and it is unlikely that you have to measure it but if you have an emergency generator you might find this circuit useful as it will give an indication whether the generator is running too fast or too slow. Actually you can....
The shift pulse amplitude is less than 15 volts. If a stage is off, the shift pulse will not be coupled to the next stage. If it is on, the diode will conduct and trigger the next stage. Just prior to the shift pulse the anode supply is interrupted to tum....
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively....
