Popular Circuits Page 131
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This power supply was designed for use with the Simple hybrid amp` published elsewhere in this issue. It is of course suitable for use in other applications as well. We`ve used a cascade generator for the 170 V, a switch mode supply for the 16 V, a series....
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Simplified circuit diagram of the two-stage Colpitts
oscillator. In comparison with the classical single-transistor
Colpitts oscillator [1,2,5] the two-stage modification
includes an extra transistor Q2 and an extra capacitor C3.
We note that both....
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This is a design circuit of audio amplifiers with DC coupling to the load are not often encountered these days, even though they offer definite advantages. One advantage is that there is no need for the complication of a second (symmetric) power supply;....
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This Design Idea offers a solution to the challenge of turning devices on or off in the past. In Figure 1, IC2 is a 555-type timer (preferably CMOS) connected as a monostable one-shot multivibrator. The pushbutton switch, S1, triggers IC2. You can replace....
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August, 2007One of my other hobbies is photography, and, about a year ago, I purchased a new digicam a Panasonic FZ30. I joined the Panasonic forum on the dpreview site. One of the posters, a programmer and electronic hobbyist, designed a nifty wireless....
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The 1812 Overture by Tchaikovsky lasts for 14 minutes and 40 seconds. It is scored for a philharmonic orchestra having up to eighty musicians, playing a wide variety of instruments. The instruments include strings: violins, cellos, basses, brass: trumpets,....
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This circuit detects low-voltage supply conditions, down to 0.6 V. Dl sets the trip point of the cir..
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This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous, unidirectional loop sequence. The circuit uses the 74LSxx family of TTL integrated logic devices. The circuits are designed to drive light....
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Four high level inputs, Double Bar switching This module can be a necessary addition to the Modular Preamplifier Control Center when more than two sources....
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It is best to remove the glass from the regulator so that you can move the regulator freely then attach the glass after you install the motor. Once you have the motor installed operate the regulator with the motor to position the glass attachment points....
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RayDialer TX1 Channel Settings = Note: Switch pulls low, if ON. DIGIT 4 3 2 1 frequencies [Hz] 1 ON ON ON OFF 697 + 1209 2 ON ON OFF ON 697 + 1336 3 ON ON OFF OFF 697 + 1477 4 ON OFF ON ON 770 + 1209 5 ON OFF ON OFF 770 + 1336 6 ON OFF OFF ON 770 + 1477 7 ON....
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Here is a simple logic state indicator to test whether the output of digital IC is in logic 1 or 0. The Bicolor LED lights Green when the logic state is 1....
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The following circuit are provded here to give your idea how the overvoltage protecton circuits really work and how you can easily add some protection to your circuits. To make theose circuit really effective need careful component choosing and good....
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Remote control circuit consists of two parts, one is the transmitter and the other is the receiver. A simple schematic diagram of the remote control. IC transmitter transmitter circuit is controlled by NE555. Receiver circuit works by the frequency of the....
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Here is a touch switch that can be used to drive LEDs, relays etc through a buffer transistor stage. It may be built around any CMOS inverter chip ..
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The speed of light has been measured many different ways using many ingenious methods. The following note describes a method which is conceptually easy to understand and fairly easy to implement. The technique is the simple time-of-flight optical pulse delay....
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Amplifier circuit with MOSFET output stage, as a substitute for the output stage based on bipolar transistors. Advantages MOSFET Amplifier : simplicity of operation, hundreds of watts with a simple parallel, negative temperature coefficient and fast....
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I would need help on converting high frequency to low frequency and vise versa. Currently I am doing a project on sensor, below is the schematic....
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Yesterday I no enhance the circuit in my blog. Today lead High Current power supply 10A and Can Adjustable Voltage or Variable Voltage Regulator 2V to 36V. By...
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The very first form of radio communication was radio telegraphy, as opposed to wired telegraphy. The telegraph key turns the transmitter on when it is closed and off when open. The operator taps out the message in a long and short, dashes and dots, code and....
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The main ΣΔloop, which again operates in steady state, is fully controlled by summing comparator Q2, which amplifies the ripples of the sensed inductor current and output voltage by gains KI and KV, respectively, to generate an internal variable s. This....
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This project combines several features in one compact unit. The fundamental driver consists of a NE 555 square wave generator. During development, consideration and a certain amount of experimentation was given to the construction of a square wave unit using....
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Many versions of VCXO`s this is the final version I have decide to use in all VCXO`s in the Future, it is extremely universal at all Freq. up to 7th Ovetone XTAL`s that can be used in VCXO. NOTE: On this CPLD PLL Board I am using a second Phase Lock....
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Accurate control of water temperature, this got me thinking and I figured it was a good opportunity to have a play. To control the temperature I decided to try and put some of the theory I was taught at uni into practice. I had it in my head even though it....
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The circuit uses AC mains voltage and otherhigh voltages that can cause injury or death. The 125 is a basic heterodyne configuration, in which the outputs of two similar radio-frequency Colpitts oscillators are fed to a mixer, producing their difference....
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The computer optimized 9 el. homebrew antenna is performing very well. I have
made many long distance contacts using the ON6MU VHF Yagi antenna. I have the antenna
located only 35 feet above the ground. (See antenna photo titled KC8VWM to
see how high it....
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This low cost water level controller circuit when built and installed will very efficiently control the level of water inside any water tank to which it s attached. Thus it can help in saving electricity and water, as well as relieving you from the headache....
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This 7-digit combination lock can be easily hard-wired for any combination that you choose. The circuit uses a 4-bit, divide-by-8 Johnson counter (IC1), ten push button switches and NPN transistor T1. At power-on, ` capacitor C2 connected to pin 15 of IC1....
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The use of logic symbology results in a diagram that allows the user to determine the operation of a given component or system as the various input signals change. To read and interpret logic diagrams, the reader must understand what each of the specialized....
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Clock signals are the heartbeats of digital systems. Hence, the stability of clock signals is highly important. Ideally, clock signals should have minimum rise and fall times, specified duty cycles, and zero skew. In reality, clock signals have nonzero skews....
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You have to admit that these tiny electronic lamps are handy, and they last almost forever. Around 40 years after Nick Holanyak developed the first LED, they have become just about indispensable. Any self-respecting electronics hobbyist always has a few in....
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This website does not collect any personal information unless you contact me by email. If you send me an email your name, email address, and any other personal information you supply will be used only to respond to your message. Your personal information....
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Trigger is applied to first of four 2-kv switch modules arranged in series, for simultaneous triggering of other modules to furnish 16-kv 20-amp pulse to type 7208 Ku-band coaxial magnetron through standard 50-ohm pulseforming network PFN. -F. A. Gateka and....
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This is a pocket-sized LED flashlight operating with only one AAA battery. However, the super high luminosity LEDs(blue,green or white) require at least 3.5 volts of forward voltage. This flashlight is boosting input voltage up to operating voltage of a LED....
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The most important part of this 88-108 transmitter is the Colpitts oscillator. C3,C4,C5,C6,CD1-CD2 ans L1 determine the transmission frequency. The RF Osci...
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If you have plane to use this Circuit on 110V 60Hz instead of 230V, 50Hz, or want to modify this circuit, Then See the Section " Common Question about this Circuit" below the "instruction". Also Note that here is two circuit diagrams, so the first one is....
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The following is the diagram of 5W audio amplifier circuit which built using power transistor BD139 and BD140 as the final gaining process. This small amplifier can be used as general purpose amplifier such as computer amplifier, radio, mp3 player, video....
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Running the Simple MT 8870 Decoder from your Cell Phone the devise can be operated from any type of DTMF tones like Land Lines, Mobiles, Computers, Radio Transmitters that send DTMF tones over the air waves, Ham Radio sets with DTMF built in to them it has a....
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Only with a single chip active component (4069 IC), this circuit will convert sine to square waves without a power-source. To test some audio instruments, we....
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A high-input-resistance op-amp, a bridge rectifier, a microammeter, and a few other discrete components are all that are required to realise this versatile circuit. This circuit can be used for measurement of dc, ac rms, ac peak, or ac peak-to-peak voltage....
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We aim to transmit more information by carrying articles. Please send us an E-mail to wanghuali@hqew. net within 15 days if we are involved in the problems of article content, copyright or other problems. We will delete it soon. ..
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This toy traffic signal uses a single low-cost hex Schmitt-trigger inverter IC (IC1a-IC1f) to directly drive three coloured LEDs (red, green and amber). At switch-on, the circuit lights the red signal for 30s, then shows green for 6s, then amber for 3s. It....
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Simulation schematic for astable multivibrator Parameters Vcc=24 Vol=1 Voh=21 Power supply Vcc Vcc 0 {Vcc} Time constant R1 Vo Vc 1K C1 Vc 0 100n. IC V(Vc)=0 * *Reference R2 Vo Vr 100K R3 Vcc Vr 100K R4 Vr 0 100K * *Comparator E1 Vo 0 Vr Vc table=(-1m {Vol}....
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can be arranged in a circle to represent the 12 hours of a clock face and an additional 12 LEDs can be arranged in an outer circle to indicate 5 minute intervals within the hour. 4 additional LEDs are used to indicate 1 to 4 minutes of time..
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Crystal is in feedback path of Pierce oscillator, between base and collector of al, with 2.5-mH RF choke in place of tuned collector circuit. Oscillator works from 400 kHz to 20 MHz, depending on crystal. Designed for fundamental crystals; third overtone....
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Probably the easiest way of doing automatic switch off is with relay logic. In the diagram, the box marked RL1 is the coil, the 2 in the coil box tells you there are two sets of contacts somewhere on the circuit, operated by this coil. In this simple....
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In a lot of cases we needed a 220VAC voltage, in spaces where it does not exist, in order to we supply with power, various small appliances. In the Fig.1, exist a voltage converter circuit from 12VDC in 220VAC, with output power roughly 50W....
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The circuit consists of a white noise generator which only switches on with the high part of the square wave output from the clock circuit. The frequency of the clock is adjusted with the 10 pot and the output voltage of the clock is adjusted by the 100 k....
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The experimenter's pot is a solid state potentiometer using Dallas semiconductor?s DS1869 and National?s LM78L05 two electrolytic capacitor two small push button switch and two optional Molex connector. this project is very useful especially in finding the....
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Can I assume that most of the 555 chips from different manufacturers are interchangable (same pin configuration), however the programs/diagrams have pins that way just to look simpler I can always route my own weird ways on the actual chip to match the....
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Might be a stupid quiestion but as 240vac-12vac transformers are readily available (and are roughly the same scale) could i use one of these in the circuit instead If the specific transformer mentioned in the schematic is not available to you, any....
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1.53 voltage controlled gain amplifier FET connected between the two inputs to the op amp as voltage-controlled resistance, resistance changes linearly with voltage, varies fro..
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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....
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Q1 and Q2 form a differential stage which single- ends into the LT1010. The capacitively terminated feedback divider gives the circuit a de gain of 1, while allowing ac gains up to 10. Using a 20-fl bias resistor, the circuit delivers 1 V pk-pk into a....
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Sawtooth wave oscillator is used in cathode ray tube deflection circuitry, in a PWM modulator, or in a analog to digital conversion. You can also use it in your...
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Power supplies that are intended to be used with TTL logic circuitry must guard against over-voltage, which can destroy TTL chips very rapidly. The duration of over-voltage that can destroy TTL chips is much too brief to trigger any conventional fuse, so....
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The ISL6405 is a highly integrated voltage regulator and interface IC, specifically designed for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise blocks (LNBs) of two antenna ports. The device is....
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Although this design is reproduced directly from the manufacturer`s datasheets, its use in this application is rather novel. Originally intended for high-visibility LED bargraph readouts, here the LM3914 is used as the basis of a 10-step variable brightness....
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There will be many times where it is desirable to use the P05 supply module from a higher voltage source. For example, if you want to add balanced inputs to a power amplifier, then you need a +/-15V supply, but the amp`s supply voltage will be much too high....
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As shown in FIG grounds MAX4450/4451 using a capacitive load drive circuit isolation resistor RISO constructed. The circuit between the output terminals and the load plus a res..
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Due to the huge interest in this project, I have just recently finished the NEW schematics. The older schematics were scanned and pretty poor quality. These new ones should make it considerably easier to recognize the parts used for the project. The Ming....
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Remote controlled light switches are becoming more and more common. DIY stores have inexpensive sets consisting of several light switches and a remote control unit. It`s then easy to control everything from your armchair. But how can you control the lighting....
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As the title indicates the goal of the project was to develop a parking lot management system. In this project we had reduced our project into 5 design phases. In order to acheive the goal, we encountered with some problems and we made progress compared to....
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This projects makes it possible to use Sega Saturn peripherals (controllers, mouse) on a PC through an USB port. Using the schematic and firmware available on this page, one can make an adapter (Using the connector from a Saturn extension) or convert a....
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Conducting pipe rechargeable long delay control circuit Adjustment potentiometer RP, can delay up to several tens of seconds. ..
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Alright, my 2204 won`t bias properly. I can`t get the tubes to idle at more than about 14 W (435 V * 33 mA cathode current). I popped a set of old Telefunkens in, but the wouldn`t go much over 10 W (440 V * 23 mA). They bias just fine in the middle of pot....
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This complete high quality, low noise 5-BAND GRAPHIC EQUALIZER circuit is based around Monolithic Linear integrated circuit LA3600 manufactured by SANYO. This circuit is very easy to build and has good Quality. You can use it with Portable component stereos,....
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IC1a, IC1b, and IC1c of the quad two-input NAND gate 4011 are connected as an astable multivibrator; IC1d is connected as an inverter. Terminals 3 and 11 of the 4011 produce square waves with opposite phases. The square waves, eP, at the output of IC1a,....
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The MAX125 and the MAX126 are complete 14-bit data-acquisition systems in which four of eight inputs are tracked and held simultaneously (Figure 1). An on-board sequencer allows the user to program which four (or fewer) channels are to be digitized.....
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This receiver weighs about 6 g, used in 41 and 72 MHz, met a great success with readers of the magazine. The RX22 is the subject of these lines is improved RX20. Adding a preamp-HF improving sensitivity. Establishment of an automatic gain control of this....
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Connection of the stator coils b Shows the structure and connections of the stator coil, and FIG. (A) shows a triangular connection, Figure (b) shows a star connection, star co..
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You are right - this was what i was talking about in my description of EM fields in the WFC - the principle is the same, the only differance....
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This PCB was inspired by Colin Fraser, who found some very useful extensions to the bass drum circuit of the Roland TR909. Trevor page`s 9090 - project was of course also very helpful for me ! As an addition to these modifications, I added a "compression"....
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The circuit shown here is used to switch on a lamp when the tele- phone rings, if the ambient light is insufficient. The circuit uses only two ICs and it can be implemented very easily. A light dependent resistance (LDR), with about 5 kilo-ohms resistance in....
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Contact resistance measuring circuit shown in FIG. It mainly consists of a constant current circuit and amplifying circuit. Operational amplifier 1C1 and form a transistor VT a..
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Circuit shown in Figure 3-143. The line not only make the braking effect of the motor is in the normal shutdown, and jog through the process and has a good braking effect. Figu..
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The full wave phase control circuit below was found in a RCA power circuits book from 1969. The load is placed in series with the AC line and the four diodes provide a full wave rectified voltage to the anode of a SCR. Two small signal transistors are....
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The charger can charge a single cell or a number of series-connected cells up to a maximum of 18V. Power transistors Q1 and Q2 are connected as series regulators to control the battery charger`s output voltage and charge-current rate. An LM-317 adjustable....
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Ultrasonic Rat Repellent circuit and Notes on ultrasonic experiments on rats....
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Using LEDs as light sensors. A DDR pad. We designed our pad to have no moving parts. Instead, we chose to measure light reflectance off the user`s feet to determine if one of the arrows was being stepped on or not. Since a design with no moving parts offers....
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AM base for small-signal amplitude modulation, the circuit as shown C is a high frequency bypass capacitor. ..
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A pair of multi-range timers offering periods of up to 24 hours and beyond. Both are essentially the same. The main difference is, that when the time runs out, Version 1 energizes the relay and Version 2 de-energizes it. The first uses less power while the....
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This humidity controlled switch circuit turns on and off an electrical load (for example a heater) depending on the moisture content of the surrounding air....
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magnetic stripe reader, electric circuit theory, logic operation: Your wiring diagram does not connect the transistor in the circuit. The collector pin of the transistor connects to the tip pin of the Jack. The base pin of the transistor connect to the....
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There are many applications where the accuracy of a digital or analogue (bar graph) is not required but something better than a simple low/high indicator....
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See as the circuit, it consists of the infrared sensor control circuit, relay control circuit, music generating circuit and so on, which can be used in infrared alarm, timing control and other spots....
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