Top Circuits Page 235
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Also called the parallel A/D converter, this circuit is the simplest to understand. It is formed of a series of comparators, each one comparing the input signal to a unique reference voltage. The comparator outputs connect to the inputs of a priority encoder....
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Restricting the resistance values between 1 k © and 100 k © for the sake of obtaining accurate voltage and current readings with your meter. With very low resistance values, the internal resistance of the ammeter has a significant impact on measurement....
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The potentiometer value is not critical: anything from 1 k © to 100 k © is acceptable. If you have built the "precision potentiometer" described earlier in this chapter, it is recommended that you use it in this experiment. Likewise, the actual values of the....
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Large-value capacitors are required for this experiment to produce time constants slow enough to track with a voltmeter and stopwatch. Be warned that most large capacitors are of the "electrolytic" type, and they are polarity sensitive! One terminal of each....
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An electronic musical keyboard as a source of variable-frequency AC voltage signals. You need not purchase an expensive keyboard for this - but one with at least a few dozen "voice" selections (piano, flute, harp, etc. ) would be good. The "mono" plug will....
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Wrap hundreds of turns of magnet wire around the paper tube. Connect this home-made inductor in series with an AC power supply and lamp to form a circuit. When the tube is empty, the lamp should glow brightly. When the steel bar is inserted in the tube, the....
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If you don`t have an audio detector already constructed, you can use a nice set of audio headphones (closed-cup style, that completely covers your ears) and a 120V/6V step-down transformer to build a sensitive audio detector without volume control or....
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Beware that not all transistors share the same terminal designations, or pinouts, even if they share the same physical appearance. This will dictate how you connect the transistorstogether and to other components, so be sure to check the manufacturer`s....
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Two NPN transistors - models 2N2222 or 2N3403 recommended. Larger "power" transistors may not exhibit the same behavior at these low current levels. However, any pair of identical NPN transistors may be used to build a current mirror. Beware that not all....
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Where can you obtain a 12AX7 tube, you ask These tubes are very popular for use in the "preamplifier" stages of many professional electric guitar amplifiers. Go to any good music store and you will find them available for a modest price ($12 US or less). A....
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The closer matched the two transistors are, the better. If possible, try to obtain TIP41 and TIP42 transistors, which are closely matched NPN and PNP power transistors with dissipation ratings of 65 watts each. If you cannot get a TIP41 NPN transistor, the....
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A oscilloscope would be useful in analyzing the waveforms produced by this circuit, but it is not essential. An audio detector is a very useful piece of test equipment for this experiment, especially if you don`t have an oscilloscope. The "555" integrated....
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The voltage rating on the 470 µF capacitor is not critical, so long as it generously exceeds the maximum power supply voltage. In this particular circuit, that maximum voltage is 12 volts. Be sure you connect this capacitor in the circuit properly,....
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This circuit uses a 555 timer to generate a sawtooth voltage waveform across a capacitor, then compares that signal against a steady voltage provided by a potentiometer, using an op-amp as a comparator. The comparison of these two voltage signals produces a....
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To begin, connect a single NAND gate to two input switches and one LED, as shown. At first, the use of an 8-position switch and a 10-segment LED bargraph may seem excessive, since only two switches and one LED are needed to show the operation of a single....
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Although the parts list calls for a ten-segment LED unit, the illustration shows two individual LEDs being used instead. This is due to lack of room on my breadboard to mount the switch assembly, two integrated circuits, and the bargraph. If you have room on....
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The model 4017 integrated circuit is a CMOS counter with ten output terminals. One of these ten terminals will be in a "high" state at any given time, with all others being "low, " giving a "one-of-ten" output sequence. If low-to-high voltage pulses are....
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This experiment is more of an introduction to the 4511 decoder/display driver IC than it is a lesson in how to "build up" a digital function from lower-level components. Since 7-segment displays are very common components of digital devices, it is good to be....
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For successful circuit-building exercises, follow these steps: Carefully measure and record all component values prior to circuit construction, choosing resistor values high enough to make damage to any active components unlikely. If there are any....
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In ladder logic symbolism, an electromechanical relay coil is shown as a circle, and the contact(s) actuated by the coil as two parallel lines, almost like a capacitor symbol. Given this knowledge, interpret the following ladder logic diagram: How do we know....
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A dimming control circuit generates a dimming control signal for determining brightness of at least one light-emitting diode. The dimming control signal has a plurality of bright-dark cycles, each of which consists of a bright phase and a dark phase. The....
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Powering up my twin digital Sony DSC-V1 cameras at exactly the same time frequently synchronizes the cameras to a remarkable degree, within milliseconds. The cameras are powered up by twinned Sony wired remotes by shorting the ACC port LANC signal conductor....
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Colour Temperature is a term used to describe the colour tonality or shade of light. As anyone who has tried to buy a tin of white paint knows well, white is a very subjective colour available in a large number of hues. We hope this guide will help you....
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This is an application project that uses software W5100 library for network connections, DS1307 for displaying time, software MAX7219 for displaying on 7-segment digits. This project displays a web page where you read the time and change the 7-segment....
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Library routines for 3-wire LCD interface based on 74HC595 shift register. More details are provided in the attached ReadMe document or posted at Do you want to unsubscribe in order to stop receiving notifications regarding "MikroC Pro for PIC driver routine....
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It is a very simple data logger project based on PIC12F683 microcontroller. The microcontroller reads temperature values from a temperature sensor on a regular interval basis and stores them into its internal EEPROM memory...
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The LT3473/LT3473A are micropower step-up DC/DC converters with integrated Schottky diode and output disconnect circuitry in low profile DFN packages. The small package size, high level of integration and the use of tiny SMT components yield a solution size....
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The LT3483/LT3483A are micropower inverting DC/DC converters with integrated Schottky and one resistor feedback. The small package size, high level of integration and use of tiny surface mount components yield a solution size as small as 40mm2. The devices....
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The LT3494/LT3494A are low noise boost converters with integrated power switch, Schottky diode and output disconnect circuitry. The parts use a novel* control technique resulting in low output voltage ripple as well as high ef ¬ciency over a wide load....
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The LT3495/LT3495B/LT3495-1/LT3495B-1 are low noise boost converters with integrated power switch, feedback resistor and output disconnect circuitry. The parts control power delivery by varying both the peak inductor current and switch off-time. This novel*....
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The LT ®4430 drives the opto-coupler that crosses the galvanic barrier in an isolated power supply. The IC contains a precision-trimmed reference, a high bandwidth error amplifier, an inverting gain of 6 stage to drive the optocoupler and unique overshoot....
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The LT5575 is an 800MHz to 2. 7GHz direct conversion quadrature demodulator optimized for high linearity receiver applications. It is suitable for communications receivers where an RF signal is directly converted into I and Q baseband signals with bandwidth....
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The LTC1046 is a 50mA monolithic CMOS switched capacitor voltage converter. It plugs in for the ICL7660/LTC1044 in 5V applications where more output current is needed. The device is optimized to provide high current capability for input voltages of 6V or....
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The LTC1754 is a micropower charge pump DC/DC converter that produces a regulated output. The input voltage range is 2V to 4. 4V for 3. 3V output and 2. 7V to 5. 5V for 5V output. Extremely low operating current and a low external parts count (one flying....
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The LTC3221 family are micropower charge pump DC/DC converters that produce a regulated output at up to 60mA. The input voltage range is 1. 8V to 5. 5V. Extremely low operating current (8 A typical at no load) and low external parts count (one fl ying....
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The LTC ®3525-3/LTC3525-3. 3/LTC3525-5 are high efficiency synchronous step-up DC/DC converters with output disconnect that can start up with an input as low as 1V. They offer a compact, high efficiency alternative to charge pumps in single cell or dual cell....
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The LTC3531/LTC3531-3. 3/LTC3531-3 are synchronous buck-boost DC/DC converters that operate from input voltages above, below or equal to the output voltage. The topology incorporated in the ICs provides a continuous transfer through all operating modes,....
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The LTC3722-1/LTC3722-2 phase-shift PWM controllers provide all of the control and protection functions necessary to implement a high efficiency, zero voltage switched (ZVS), full bridge power converter. Adaptive ZVS circuitry delays the turn-on signals for....
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The LTC ®4241 is a Hot Swap controller that allows a board to be safely inserted and removed from a live PCI-bus slot. It has a primary controller that controls the four PCI supplies and an independent auxiliary controller to controlthe 3. 3V auxiliary....
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The LTC4251/LTC4251-1/LTC4251-2 negative voltage Hot Swap controllers allow a board to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current limiting: a timed circuit breaker, active current limiting....
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The LTC ®4251B/LTC4251B-1/LTC4251B-2 negative voltage Hot Swap controllers allow a board to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current limiting: a timed circuit breaker, active current....
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The LTC4425 is a constant-current/constant-voltage linear charger designed to charge a 2-cell supercap stack from either a Li-Ion/Polymer battery, a USB port, or a 2. 7V to 5. 5V current-limited supply. The part operates as an ideal diode with an extremely....
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The RH1078M is a micropower dual op amp in the standard 8-pin configuration. This device is optimized for single supply operation at 5V. Specifications for ±15V are also provided. Linear Technology offers many demo boards free of charge to qualified....
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There are 3 basic types of earphones, each with their set of benefits and problems. Small transducers that are inserted into the auditory canal. This leaves only a few millimeters of a mismatched acoustic transmission line between the vibrating diaphragm of....
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Based on the SN74LS194 - Bidirectional Universal Shift Register the circuit is designed to drive UNIPOLAR type stepper motors and provides only basic control functions - Forward, Reverse, Stop and Speed adjustment. For the purposes of this page the direction....
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We used as a starting point for our experiments, the switching device John Bedini had built for the Tesls Symposium. Our goal was to upgrade this switching device for ordinary car or motorcycle batteries....
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The input range of the USB-DUX sigma board (+/-1. 35V) matches perfectly the output voltage range of the LM35. GND is available on many pins on the HD connector (check out the pinout ) so that you can choose the ones which are easiest to solder to. R5 should....
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A pre-requisite for this article is that you have the GCC AVR programming environment installed as described in my "Programming the AVR microcontroller with GCC, libc 1. 0. 4" article. If you want to avoid troubles with the installation you can of course use....
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The Atmega8 microcontroller from Atmel has plenty of digital and analog input/output lines. It is the ideal device to develop any kind of measurement equipment. A pre-requisite for this article is that you have the GCC AVR programming environment installed....
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This article is the result of the very positive feedback on the hardware articles that I have written so far. You LinuxFocus readers are really a great audience! Some of you wanted to know how to interface the USB bus. So here is a nice solution. We use the....
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The AVR 8-Bit RISC microcontroller from Atmel is a very common microcontroller. This microcontroller is one chip with EEPROM, Ram, Analog to Digital converter, a lot of digital input and output lines, timers, UART for RS 232 communication and many other....
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This article continues the AT90S4433 Microcontroller series. I suggest you to read the previous articles on Atmel Microcontroller programming with regards to: This time we design a frequency counter which can measure frequencies from 1Hz to 100MHz.....
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The ELM622 by ELM Electronics is a preprogrammed PIC which converts commands from a Sony infrared remote control into a serial data stream. An IR receiver using a ELM622 requires no kernel modifications. This project shows how to build a Linux IR receiver....
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Today may of our appliances come with displays and buttons. Instead of motors and gears, many household items today have embedded Microcontrollers. We are going to explore how we can experiment with Microcontrollers at home....
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The programmer uses serial signaling scheme to program the chip in circuit. The signaling is carried through the programming clock (PGC or ICSPCLK) and the programming data (PGD or ICSPDAT) pins. In addition, the MCLR/VPP pin is used as either a high voltage....
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The new project uses old analog satellite receiver tuners that have to be modified so that the AFC is disabled and the AGC usually set to maximum gain. The output is the 480MHz IF signal. The IF converter can be for example a Satellite receiver with 70 MHz....
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You need a TSOP4156 which can be a tough one to get or expensive to buy. I had plenty of old BPW41 Infrared diodes so I decided to build my own receiver. The power comes from the RS232 port, make sure you have at least 5. 5 Volts or the 4001 will not....
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This design is for PC Soundcards obviously. If you need an interface for a Mac see my other page. For other computers and PCs without a soundcard you might take a look at Harmony Central`s interface page. I have built one of these myself, exactly as....
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This instrument is a computer controlled acoustical angklung designed and build in 2000. In 2006 it has undergone a major upgrade of the entire hardware. The anklungs themselves are made of hardened brass and tuned to a western scale covering two octaves.....
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This project describes an easy and inexpensive way of adding a digital thermometer and data logging feature to a PC. It involves a PIC microcontroller that gets the surrounding temperature information from the Microchip MCP9701 sensor, and sends it to a PC....
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The purpose of this page and its sub pages about members of Z80 family (and close relatives) is to collect and share information and good ideas. I know there are lots of people out there, who have developed some good utilities and hardware solutions. Now we....
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Okay, I ve decided that I want Daytime Driving lights for my Elise. Also I don t want to keep pressing the button on and off each time I....
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Complete wireless product development by LS research. Specializing in RF Design, WiFi modules, Antenna Design, Zigbee, Bluetooth and more....
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Homebuild Basic Plotter / Engraver / Vinyl-cutter / PCB-driller a basic program reads a HPGL file and controls stepper motors connected to parallel port....
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The oscillator circuits presented on this page are from expired or non-maintained U. S. Patents. All circuits are presented in "Electronic Workbench 5. 12" or "Multisim 7 circuit simulation formats". A note on spice simulation of electronic oscillator....
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CMOS analog multiplexers were frequently used at the ETC for various purposes. Here I thought I would present a circuit I borrowed from a Dave Jones design, and slightly modified it, to build a black burst generator. Video systems need sync to ensure that....
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Here is another example of using a CD4051 multiplexer, or more accurately a pair of CD4051s in parallel. I had lifted much of the core logic and circuits from Dave Jones designs. Again these are old designs offered from a historical perspective. I built this....
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BC547 transistor. Max operating current is 100 mA while max voltage is 65 volts. With the transistorlabelfacing the reader, the three legs from left to right are collector, base and emitter. Note: I destroyed one BC547 transistor while setting this up. I....
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USB flash drives provide a handy way to store any type of information in a small package. The drives, also known as thumb drives and USB keys, seem ideal for use in data loggers and other microcontroller-based projects. But to access files in a flash drive,....
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When a network needs to transfer small blocks of information over long distances, RS-485 is often the interface of choice. The network nodes can be PCs, microcontrollers, or any devices capable of asynchronous serial communications. Compared to Ethernet and....
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The SDR hardware in its simplest form consists of a wideband switched balanced mixer and low noise LF amplifier. This simple hardware has an amazing sensitivity and linearity which is sufficient for test and even regular use. Here are some of the problems in....
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There are now extremely wideband software defined radios (SDR) where the wideband antenna is a natural choice. Wideband small magnetic loops (WSM loop) are used already 3-4 decades and I was curious to see what can be reached with them and to evaluate their....
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A larger version of the circuit diagram by clicking here. The circuit was drawn using Eagle from CadSoft, a schematic and PCB layout package that is free to use for small non-commercial projects. The heart of the keyer is the PIC16F877A chip. This is a 20MHz....
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Using this schematic I doubled the range of my IR LED, the power drawn in the circuit is now 37mA. My former circuit, without using a NPN transistor drew 20mA (JeeNode max per digital pin). So that`s almost twice the power. You could increase this even....
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When the receiver is tuned to a M. W. radio station the resulting feedback howl, caused by the transmitter can be set to alter, or appear when the coil and radio are above or near a metal object Here is a pictured of the search head. It is made from a....
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Acrylic Plastic, Aluminum Beverage Can, Ammunition, Antilock Brake System, Asphalt Cement, Balloon, Barbed Wire, Baseball Bat, Bathtub, Beeper, etc....
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Implementation of CAN for use in aircraft. The protocol is called CAN-FIX and is a part of the MakerPlane Open Source Airplane project. You can get more information on CAN-FIX here. The idea for this project is to build an Arduino shield that will let it....
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The phone is a Siemens S65. The official charger that came with the phone says 5V at 420mA. Because these things do not always actually deliver what is printed on them I measured the voltage myself. This is actually quite hard with the tiny contacts on the....