Popular Circuits Page 119
- Page 119
-
This device beeps intermittently for about two seconds when a person in a range of around 10 meters emits a whistle. The first two inverters contained in IC1 are used as audio amplifiers. IC1A amplifies consistently the signal picked-up by the small....
-
-
-
Burr-Brown DRV134 AUDIO BALANCED LINE Receiver schematic PCB/Kit anybody? I want to make a Balanced Line RECEIVER using the DRV134. Could anybody....
-
A normally open pushbutton switch (SI) delivers a positive input pulse to pin 4 of Ul, triggering the 1C into action. The output of Ul at pin 6 supplies base-drive current to a Darlington pair comprised of Q1 and Q2, activating . 10- capacitor and any....
-
This easy to build FM transmitter bug can transmit voice to exceptionally good range. Tune trimmer to hear the signal to your near radio. Transmitter frequency range is 88-108 MHz. Max current consumption is 30mA. You can power the fm transmitter bug with a....
-
The circuit given here can be used for tossing head or tail. There are many games in which a tossing is required to start and this circuit can be used in all such instances. The circuit uses two ICs NE 555 timer (IC1) and 74LS76 dual JK flip flop (IC2). The....
-
-
This LED Flasher circuit is based on the 555 timer IC. The LED Flasher circuit diagram is very simple and require few external components. When the circuit is working the red LEDs will flash at a set frequency one by one like at the railway crossing....
-
Here`s a small LM386-based square-wave oscillator built from the following schematic. I replaced the 30k resistor with a 50k Potentiometer from my stash of parts which then, of course, acts as a pitch controller. The following audio is some track recordings....
-
Bridge the digital pressure signal conditioner MAX1458 excitation circuit is shown. Using the output DAC3 to change the size of the sensor excitation current IBR, you can achie..
-
In order to accomplish this my initial thought is to sample an input (ADC) at consistant time increments and then display the waveform on a graphic lcd display. If I want to change the time scale I can just change the rate of time between samples, and if I....
-
In this project, you will make a simple low-power broadcast-type circuit, using a crystal oscillator integrated circuit and an a collector modulated AM oscillator. You can connect the circuit to the an amplified microphone (no amplified microphone has a to....
-
-
I have an automotive relay (from a scan of a workshop manual I`m afraid) which is rather more complexly wired up than the relays I`m familiar with. In this diagram: B/G - holds high if another condition is met (engine temp too high), to prevent the relay....
-
The FT-736R is a V/UHF all mode transceiver. A picture of the FT736R can be seen in figure 1. This article will show how you can modify the AGC (Automatic Gain Control) circuit to disable it. When you are doing radio astronomy it ’s vital to be able to....
-
Probably the best advantage is its very small size and the fact that it can run off the power supply of the circuit being tested. Although it has a low frequency range, it can still be used for most circuits. Its poor resolution will still allow for most....
-
LM1036 is a DC controlled tone (bass/treble), volume and balance circuit for stereo applications in car radio, TV and audio systems. Component: ...
-
An electronic dice is a classic first project for those getting interested in electronics. A timer, counter and a few LEDs makes a circuit that can also add a new twist to some old boring board games. When the switch is pressed, a 555 timer in astable mode....
-
The circuit exemplifies the use of ZN414 IC to produce a handy AM radio receiver. ZN414 IC a composition of transistor tuned radio frequency (TRF) circui....
-
As shown in FIG constituted by OPA340 INA321/322 output buffer circuit. INA321/322 optimum load impedance 10k or more. When the load impedance decreases, the output current wil..
-
Major role in the PLL phase detector is held by the duty comparing the input phase of the VCO signal with a reference signal and the output is a different phase. The existence of different phases will provide a further voltage difference, the difference....
-
Do not let its extreme simplicity deceive you — this thing is useful! I have made many over the years and have even given some away as gifts. Yes multimete....
-
JFET input. PN photodiodes such as the popular "bullet cell" put out an extremely low-level signal. Yet photodiodes offer advantages over phototransistors. For example, more rapid response to motion. Also, some photodiodes have a peak response in the range....
-
Going camping nowadays involves taking lots of electronic equipment whether for day to day running or for fun and entertainment. Most of the time a charged lead acid battery and a power inverter would be used to ensure a smoothly organized holiday where....
-
A recent Design Idea prompted me to offer the simpler solution that I used in a recent project (Reference 1). We needed a momentary power switch with processor supervision. This supervision would allow the processor to delay a power-down request from a press....
-
wireless audio and visual transmission to a TV. The TV acts as a receiver, eliminating the need to buy a separate monitor. You can also hook it up to a VCR or CCD Camera, and even set up a remote CCTV security system Q3, VC1, C13, C16 and L3 all make up a....
-
The on-hook (no load) voltage across the red-green wires will be 48 V or slightly less when all telephones are on-hook (disconnected). When any telephone goes off-hook the load current flowing in the telephone causes the voltage to fall below 5 volts dc.....
-
Voice circuits described in this section, during the day or in brighter, voice-activated switch is turned off, the lamp does not light. At night or in low light, sound control switch is pre-working state...
-
Check the following IC`s7400, 7402, 7404, 7408, 7432, 7486. Visual Basic Program is used to show the results on the PC. The Microcontroller AT89S52 receives the IC number from the PC and check the Gates IC with the Truth table and sent back the result to the....
-
The CAMD CM8870 CM8870C provides full DTMF receiver capability by integrating both the band-split Filter and digital decoder functions into a single 18-pin DIP, SOIC, or 20-pin PLCC package. The CM8870 70C is manufac- tured using state-of-the-art CMOS....
-
The circuit forces a current to build up in the L1 coil and the LEDs until the voltage developed across R3 reaches VFB/3.3V. At this point, power switch Q1 turns off, and the magnetizing current keeps circulating in the coil and LEDs, thanks to....
-
Telephone Tone Ringer TA31001 The UTC TA31001 is a bipolar integrated circuit designed for telephone bell replacement. It CAN also be used as alarms or other alerting devices. By LianShun Electronics Co. , Ltd ..
-
Here s a project that could be useful this summer on the beach, to stop anyone touching your things left on your beach towel while you ve gone swimming; y....
-
When this circuit is connected to a filter and an oscilloscope, the scope displays the filter"s frequency response. A..
-
At present, the switching power supply is with its high performance, high efficiency 75%, the switching power supply efficiency of the single scale integration has already been more than 90% now, This pair solves the energy problem and plays a role in adding....
-
Using PIC16 simulator (Proteus) you can verify this digital clock code and change it according to your needs. Using three push buttons (As shown in figure below) you can adjust time as you desire. This code is written in C language using MPLAB with HI-TECH C....
-
Uses controlled variation of amplifier bias current IABC in CA3080A variable opamp to obtain effective gain control of signal. Variations in amplitude of modulating voltage Vm change bias current through Rm to give amplitude modulation of carrier. -"Circuit....
-
A JFET (Ql) serves as the oscillator. D2 helps to stabilize the transistor by limiting positive sinewave peaks and stabilizing the bias. Output from Ql is supplied to a class A buffer, Q2. It operates as a broadband amplifier by means of Tl, which is....
-
-
You can use any PIC microcontroller that has an ADC and enough memory to hold the program. The LED is pulsed after every ADC acquisition to indicate that the processor is alive - so you can tell if the software is active. You can recompile the lcd volt....
-
This electret microphone amplifier is designed using common electronic components. This microphone amplifier uses an electret microphone capsule, but can be an dynamic microphone, which have a low resistance. This circuit requires a supply voltage between 5....
-
This tester is for tracing wiring on Printed Circuit Boards. Resistors below 50 ohms act as a short circuit; above 100 ohms as an open circuit. The circuit is a simple multivibrator switched on by transistor T3. The components in the base of T3 are Dl, Rl,....
-
The 16F84 has 13 outputs. All 13 can serve as inputs, but only 12 are normal outputs, one is an open-drain. An open-drain output has no active pull up- you have to provide an external (passive) pull up. Since the `F84 is CMOS based, this leaves us 12 outputs....
-
The major advantage of amplifiers of this type is that the normal static power dissipation is very low, and the overall power-conversion efficiency is high. Unfortunately there are also some inherent disadvantages due to the intrinsic dissimilarity in the....
-
Recently many kind of robot contests have being opened and some interesting reports of the challenge are found on the web. The Line Following is a kind of the robot contests to vie running speed on the line. I build a tiny line following robot which can run....
-
This simple circuit providers battery operated emergency lighting instantaneously upon failure of the regular ac service. When line power is restored, the emergency light turns off and the battery recharges automatically. The circuit is ideal for use in....
-
This monitor uses a common 7 41 amp configured as a comparator and a low cost nontransistor as an output driver. With no liquid detected, a voltage of about 2. 92 V is present in the op amp"s inverting input at pin 2. The 100-KO resistors establish a....
-
The design uses tactile sense (or rather, neural sense) to reveal the contents of a box. The box contains 4 shapes, as in a child`s shape sorter. The conjurer asks a person to secretly remove from the box any shape or shapes of his or her choosing, then to....
-
Minimum Voltage required for this circuit 8 volt and maximum voltage 28 volt. Its can use to amplifier on the electronic devices such us Radio, DVD, MP4, MP5, and etc. To amplify the signal sound to audio sound, Maximum output power 2 x 20 Watts with....
-
This method is sometimes impractical, however, because it cannot check for short circuits. The method shown in Figure 1 solves the short-circuit problem. Connecting LED indicators at each shorting loop provides a visual indication. The beauty of this scheme....
-
Voltage controlled oscillator (VCO) is similar to a voltage to frequency converter (VFC), an oscillator which its output frequency is determined by a control voltage input. This is the figure of the circuit; Where d is the amplifier input voltage = 0. 6V,....
-
For the MAX712 charger is needed a power supply with a output voltage with at least 1. 5V higher than the maximum battery voltage. Charge completion is determinate by a voltage-slope detecting analog-to-digital converter, timer, and temperature window....
-
The following is a method to allow day and night detection using Infrared/Visible light sensitive phototransistors and a simple LM339 voltage comparator circuit. A phototransistor is mounted between the rails so that it is covered by the train as it passes.....
-
This circuits consist of two parts, the first part will transmit a signal, and the second part will detect that signal and trigger a relay.To adjust the circuit, hold down S1 while pointing LED1 at the receiver. Adjust R6 until you hear the relay click. You....
-
Even though i had isolation at the sensors and actuators to make doubly sure the PC also has been isolated. There are chips that are available for this purpose, The circuit above is built with discrete and passive components except for the opto 4N35. You can....
-
The amplifier is capable of delivering around 1.5W into 8 ohm headphones, and 2.2W into 32 ohms - this is vastly more than will ever be needed in practice. The use of a 120 Ohm output resistor is recommended, as this is supposed to be the standard source....
-
The Link circuitry is simple and efficient, employing just two ICs, half a dozen transistors, and a handful of garden variety components. It all runs on 12 volts and is easily assembled. You can have your own home intercom between the kitchen, the garage,....
-
I`m currently using a Gecko G540 drive module to drive the stepper motors. This module has the ability to drive up to 4 stepper motors. They label the connections as XYZA - we`ll connect the C-axis stepper to the A output and leave the Y output unconnected.....
-
-
Figure 99-l(a)"s circuit exhibits a high-output impedance as a result of the small effective capacitance of the series-c..
-
-
This device is a simple timer, allowing to keep on the headlights of your vehicle for about 1min. and 30sec., e.g. when accessing some dark place, without the necessity of coming back to switch-off the lights....
-
-
An IR-sensitive phototransistor is used to sense soldering-iron temperature. The phototransistor must see t..
-
Dear friends i need your advice about the connection diagram of the MAX4685 analog switch attached. I have two inputs VI1 and VI2 and hence we have....
-
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....
-
The circuit described here is that of a metal detector. The opera- tion of the circuit is based on
superheterodyning principle which is commonly used in superhet receivers. The circuit utilises
two RF oscillators. The frequencies of both oscillators are....
-
-
This is a schematic and block diagram of a 2-MHz frequency counter. It uses and LSI counter/display driver, LCD readout, and a, few logic chips for timebase and timing pulse circuitry. Q2 and Q3 form a signal (input) amplifier. The circuit contains a crystal....
-
The LinkSwitch-XT LNK363DN based‚ flyback power supply shown in Figure 1 generates a single isolated DC output voltage from a 90 VAC to 264 VAC input voltage range. The power supply output is 5 V, 550 mA (2. 75 W) constant-voltage/constant-current (CV/CC).....
-
-
This circuit allows zero adjustment as well as slope adjustment. The ICL8069 brings the input within the common-mode range, while the 5 K pots trim any offset at 218 °K (-55 ƒ), and set scale factor. ..
-
-
This is the giant controller used for the game Steel Battalion for the xbox. I used this schematic diagram from a guy called Alpha who did it to his....
-
The circuitry for a hot swappable PCI slot on a motherboard or backplane is shown in Figure 1. The power supplies for each PCI slot are controlled by an LTC1421 and four external FETs, and the data bus is buffered by several QS3384 QuickSwitches or....
-
This tour, available in Stainless DIL 8 legs, can measure 4 analog voltage independent between 0 and 5 volts, and send the result of this measure in the form of four characters on a standard asynchronous serial link. Its serial output is directly TTL or CMOS....
-
-
-
This tutorial continues on from ATmega8 Breadboard Circuit Part 1 where we build a small power supply on the breadboard. In this part we will add the ATmega8 microcontroller and an interface to allow it to be programmed. The first step is to orient yourself....
-
The following diagram is the circuit diagram of 20 band stereo graphic equaliser which will controlling the audio signal in specific frequency range. This circuit must be connected before the amplifier circuit. For maximum performance, you....
-
A 2 Watt audio amplifier made from discrete components. This was one of the earliest circuits that I ever designed and built, in Spring 1982. At that time I had only an analogue meter and a calculator to work with. Although not perfect, this amplifier does....
-
This design for a headphone amplifier arose after the purchase of commercial equipment with separate pre and power amplifiers without a headphone output. Its advantages are ...
* low output impedance to drive several pairs of phones
* the active....
-
Circuit is shown. Motor using series resistance in the rotor winding start. Drawing, electrical velocity off the relay KIi ~ KI3 for motor short circuit protection; overcurrent..
-
It is on top labled toy car receiver. The toy car transmitter is easy enough to understand, and I suspect that the receiver is essentially working the same way, but backwards and with more filtering. I have no experience in RF except that I saw this circuit....
-
It doesn`t break if being little even if it crosses the value of the input/output electric current characteristic. It breaks when short-circuiting and doing the extreme thing in the output. It is explained by the following circuit operation but because the....
-
The AM Transmitter circuits in two and a half, audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. Tank circuit L1 and VC1 is melodious from about 500kHz to 1600KHz. These components can be used from an old MW....
-
Control monitoring equipment at a TV repeater site. It had to accept commands sent as DTMF tones over the repeaters audio channel and be able to switch either AV signals or power supply feeds at currents up to 1 Amp. The switching requirements left no option....
-
-
Here is a simple 2. 4 GHz SWR meter which can be easily found, which is based around surplus microwave hardware. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2. 5 GHz. This particular....
-
An oscillator-only transmitter sounds like the simplest possible means of getting on the radio air ”until you consider the challenges it presents as part of the system that is a transmitting and receiving station: The problem of an adequate....
-
This document describes a simple SWR-meter suitable for long and medium waves bands (137 and 500kHz). The design is nothing new and very similar to common short wave meters, but it has been designed to work with low frequencies. The majority of amateur radio....
-
The circuit described below monitors your car`s brake lights, and indicates by a light emiting diode whether they both function correctly. In that sense, it can save you money by preventing your being fined for driving with defective brake lights, and it....
-
-
A simple tutorial on using ADC (Analog to Digital converter) unit of AVR micro controller illustrated using Atmega8 with circuit diagram & codes....
-
This application note discusses the application of Avago Technologies` MGA-675T6 for 5-6 GHz application. The MGA-675T6 is integrated internally with shutdown and biasing circuitry. Besides reducing the complexity of the external circuitry, the shutdown....
-
-
-
The following circuit shows about Mains Remote-Alert Circuit Diagram. Features: simple circuitry, the transmitted signal is conveyed into the ...
-
Batcopter was built for Stanford`s first of three Mechatronics courses, ME218A. It is a mechanical version of the classic flash game Helicopter. The game has additional interactions for added complexity including enemies & different modes of difficulty. It....
-
This circuit turns-off an amplifier or any other device when a low level audio signal fed to its input is absent for 15 minutes at least. Pushing P1 the device is switched-on feeding any appliance connected to SK1. Input audio signal is boosted and squared....
-
I have a Chemetron wirefeeder that I am using the motor and I want to use the speed control out of the control box to control the nice motor it had in ....
-
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,....