Top Circuits Page 258
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The remote control electric hoist control circuit consists of the wireless transmitter, wireless receiver control circuit and the main control circuit. Wireless transmitter uses TWH9326 four key BP transmitter. Wireless receiver control circuit consists of....
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The remote control robot circuit is as shown in the figure. The figure 2-36(a) is the circuit diagram, the figure 2-36(b) is the operating timing diagram. The rotation process of the rebot is: in the circuit, the ultrasonic launching circuit is composed of....
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The SC41343 is designed as one kind of infrared, ultrasonic or RF remote control launch coding circuit. The internal circuit is composed of the sequence generator, control logic circuit?4-bit shift register?data extraction circuit and the latch circuit.....
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The SL517 is designed as the audio, RF or infrared decoder circuit that can be used in the electronic toy application. The internal circuit is composed of the analog amplifier, the frequency divider, the bistable circuit and the driver. Features It uses the....
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When the current is less than the value set, the bias current provided by R1 leads the P3 to be saturated to conduct. And it can not afford to control the current. When the current is greater than or equal to the set value, the pressure drop on R would....
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In this figure S1 can start timing and when the timer starts, turning this switch has no effect.S2 is the OFF switch in the middle and turning this switch can make the timer complete the procedure: charging-open circuit-discharging. Because of charging....
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In the figure is the FM modulation circuit of crystal oscillator. FM modulation has direct and indirect FM ways, the direct FM method is to directly change the frequency of the oscillating circuit, it`s simple, but as it is the LC oscillating circuit, the....
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See as the figure, the controller consists of liquid level, trigger controller and step-down rectifier circuit, etc. The water level detecting poles of a, b and c compose the bias circuit as the water level detector with W1, R1, R2 and R3. When the water....
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Is an eight-way signal remote control selection circuit composed of ZHJ-9904 ; (B) is remote control transmitter circuit; (C) is the eight-way switch control circuit; (D) is remote control transmitter...
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This is the electric thermometer circuit composed of LM134. In the circuit, the voltage or current output by LM134 is in proportion to the thermodynamics temperature, which can be read out on the 100?A meter, the test temperature range of the meter is....
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The switch shut off time delay circuit is shown as below. The switch shut off time delay circuit is composed of the timer, optocouplers, bridge SCR, SCR AC switch. When the control button is released, the keeping motor or other AC start power for 1 hour.....
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When this thermometer is used in the room, it can work in the intermittent way, and this working state can be kept in the temperature test circuit, because internal temperature doesn`t change sharply. The astable multi-resonance oscillator consists of VT1....
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It can set delay time according to the voltage Us and resistor R. In the circuit, S1 is the the discharge switch of capacitor C. When the switch S1 is closed, the stored charge on C will be released through S1 to ensure the accuracy of the delay time the....
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Wireless remote control transmitter circuit is composed of control buttons S1 ~ S16, resistors R1 ~ R3, capacitor C1 regulator diode VS, crystal oscillator BC1, DTMF encoder IC IC1 and IC2 wireless remote control transmitter integrated circuit components. It....
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This wide-range light dimmer circuit uses a unijunction transistor and a pulse transformer to provide phase control for the TRIAC. The circuit operates from a 115 volt, 60 Hz source and can control up to 800 watts of power to incandescent tights. The power....
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741 opamp is connected as audio oscillator with Radio Shack 276-677 photocells in feedback circuits. When light strikes PC1, its resistance decreases and frequency of audio tone in headphone decreases correspondingly. When light strikes PC2, which is....
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This circuit is composed of the light measurement circuit and the flash circuit, as the figure shows. It can be used in the POPTICS (one kind of popular integration camera), the Franka X-500 and the WIZEN-860S cameras. It is composed of the following....
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The temperature measuring range of this electronic thermometer is 0-50?, the precision is 0.1?, the measurement results are intuitively displayed by digital display. This electronic thermometer circuit is composed of temperature detection circuit, monostable....
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Pyroelectric infrared sensor head is same with the figure. When it detects the human body infrared signal in guarding zone, the sensor head will output a positive jump pulse signal, this signal is added to input terminal P point. IC1 adopts 555 time base....
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In the silicon-controlled trigger circuit, cadmium sulfide cell connects the relaxation oscillator before having a sensor to blink in darkroom. That make the speaker emit the warning sound of Ka, Li. The rate of the sound will increase with the quantity of....
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This DIY magnetic field sensor circuit is very simple and can detect fixed magnetic fields or fields that are varying at an audio frequency. The unit is not intended to provide accurate measurement of magnetic field strength. A small and not very powerfull....
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The circuit is formed by light metering circuit and flash circuit,just as shown in picture.It is suitable for POPTICS (a popular integrated camera), Franka X-500, WIZEN-860S and so on.It consists of the following circuit:(1)VT1,VT2,light metering device RG....
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This circuit includes micro vibration sensor, trigger delay circuit and control circuit, the figure is as shown. The micro vibration sensor contains vibration sensor device and high power amplifier circuit, it can induce very weak external vibration signal,....
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The LM35 temperature sensor provides an output of 10 mV/ƒ for every degree Celsius over 0ƒ. At 20ƒ the output voltage is 20 x 10 = 200 mV. The circuit consurnes 60 A. The load resistance should not be less than 5 k ©. A 4- to 20-V supply can be used. (View)....
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This is a luminous flux test circuit with optical resistors. In the circuit, the optical resistor RG forms a bridge with RP1,RP2,R1 and R2; RP1 is used to adjust the balance of the bridge; RP2 is used to adjust the sensitivity of the circuit. If we adjust....
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The figure is a schematic circuit of UV sensor. When UV sensor is coupled by voltage between the cathode and anode, and the UV radiation gets through the quartz glass tube on the cathode of the optical surface, because of the cathode material coated with....
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To use the circuit you will need a wind vane like the one shown. It should have a weighted front end and an air paddle in the rear. Attach a small, strong magnet to the front part of the wind-vane arm. Then, position eight reed magnetic switches in a circle....
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The circuit SJT is a 1024kHz warming crystal oscillator. Circuit is shown as the chart. As its output signal level is low, so the following transistor VTl is used as the buffer amplifier. The base bias resistor R2 of VTl, the load resistor R3, the emitter....
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The oscillator circuit which is composed of the 1MHz quartz crystal resonator and the NAND gate is as shown in the figure, the NAND gate 3 is the output buffer stage. This circuit can be used to calibrate the standard frequency. Figure 1 The 1MHz quartz....
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A 27MHz NBFM transmitter circuit schematic with MC2833 and 2 FET transistors MPF6660. Using a Motorola MC2833 one-chip FM transmitter, a few support components and am MPF6660 RF amp, this transmitter delivers up to 3W into a 50 ? antenna. It is capable of....
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The 27MHz quartz crystal oscillator circuit is as shown in figure 1. The biasing circuit is composed of the R1, R2 and R3, C6 is the bypass capacitor. The partial voltage circuit is composed of the C1, C2, C3 and C4 to control the strength of oscillation. L1....
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As the figure 14-17 shows, this circuit is composed of the input circuit, the line frequency synchronization generator, the sample-and-hold circuit, the voltage control delay generator and the RF modulator.The input circuit is composed of the input....
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As the figure 14-41 shows, the multivibrator is composed of the 555 and some capacitance resistance components, the oscillation frequency depends on the values of Ra, R16 and C3. f=1.44/(Ra+2R16)C3, the Ra of the formula corresponds to the different values....
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The electronic switch is composed of the CK-4 type magnetic control switch and the VT1?R1?R2. When the bathroom door closes, the permanent magnet ZT and the reed pipe GA get close to separate the two touch tablets of GA, VT1 cuts off, pin-2 of IC has the....
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As shown in Figure it is 567 FM demodulation circuit. In the figue, the FM signalenters from the 3 foot, the demodulated signal goes out from 5 foot. FM signal center frequency which the circuit can demodulateis: fo = 1.1 / RC, C1 isfilter capacitor, and C2....
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Using an EXAR XR2206, this generator will produce sine, square, and triangular waves from Hz to 100 kHz. U1 is the XR2206 chip, R7 controls frequency, and 55 through 58 select the frequency range. U3 produces a TTL-compatible square-wave output, while U3C....
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Combines signals from loop and sense antennas of automatic direction finder, to give 130-cps output having correct phase for driving rotor of resolver to null position.-P. V.Sparks, Servo Filter and Gain Control lmprove Automatic Direction Finder,....
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Here`s BH1417 USB FM Transmitter with built-in PLL circuit. Its low-frequency signal is converted into high-frequency, which can take any audio device with FM radio (stereo, car CD, MP3, DVD player, etc.), as a normal radio station. Transmitter power is....
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When low/high input is voltage in binary form, as obtained from converter circuit (also given in artide) fed by digital voltmeter, circuit produces Iow pitch for binary 0 and high pitch for binary 1 when S2 is set at D for digital voltmeter mode. Recognition....
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This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery.....
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The RF oscillator using the inverter N2 and 10.7Mhz ceramic filter is driving the parallel combination of N4 to N6 through N3.Since these inverters are in parallel the output impedance will be low so that it can directly drive an aerial of 1/4th wavelength.....
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Circuit`s Functions The frequency modulation FM transmitter which can be used in 76~90MHZ FM radio band, usually also it is called wireless microphone.It adopts signals via FM radio receiver.The signals can be transmitted in wireless means if we don`t use....
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Here`s simple FM transmitter circuit using medium power 2N2218 transistor. Micropohone is of electret type that connects to two input terminals and the antenna should be a copper wire from 15 to 40 cm. Below is schematic circuit of the fm transmitter....
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On frequency stability, the quartz crystal oscillator circuit is very advantageous, even the the VCXO circuit with large amount of frequency changing only changes about 1%, and the linear range of control voltage to frequency variation is not wide. Although....
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Frequency signal tracking circuit is the phase-locked loop circuit, which is one of the basic application circuit of CD4046. The circuit shown as the chart and composed of CD4046 is a PLL circuit, and it can capture and track the input signal with the input....
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Internal telephone circuit is shown as below,improving slightly a toy telephone will become a variable practical internal telephone. This phone is compose of the phone component,decoding circuit,ringing circuit and other components. Using more than two the....
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Telephone electronic coded lock circuit is shown as above,the electronic coded lock is suitable for double audio circuits.After the phone adds this coded lock, when you call out,you must use the buttons on the phone to press the four pre-programmed....
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Telephone electronic ringer circuit is shown as above,Figure (a) is the electronic ring circuit with an NPN transistor V1 (choose 9014 or 3DG12) as the core, sound devices YD is also feedback devices composed of the feedback pole and the buzzer equipped with....
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The chart shows a function generator circuit composed of 555 timer. The circuit consists of a CH7555 timer and some transistors and RC components. It can generate triangle wave, square wave, sine wave, sawtooth and square wave sweep simultaneously. Ramp can....
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This high voltage generator can generate stable high voltage above 8kV. Its circuit is simple. It is stable and reliable. This circuit includes step-down rectifier, voltage regulator circuit, 18kHz multivibrator type oscillator and booster transformer, etc.....
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Square-wave generator with LC circuit can get a better frequency stability, it`s as shown in the chart. This three-terminal oscillator of capacitor can be used to generate a square wave, but an operational amplifier is used as the active component....
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The linear charging ramp is most useful where linear control of voltage is required.Some possible applications are a long period voltage controlled timer, a voltage to pulse width converter, or a linear pulse width modulator. Q1 is the current source....
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In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a....
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FM Transmitter is very simple, compact, and has transmission signal with a range of 100-150m, good sensitivity and low current consumption. Transmitter`s schematic consists of a bass amplifier for the first transistor and the proper frequency generator in....
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This circuit SJT is 1024kHz temperature compensation crystal oscillator. Circuit theoryis asshown. Because output signal level of the circuit is low, the buffer of follow-up transistor VTl is amplified. VTl base bias resistor R2, the load resistor R3, the....
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Simple network design is a key feature of the Pierce circuit, as these 1-MHz oscillators illustrate.Operating the crystal slightly above resonance (Fig.21-5a) requires only one high-gain transistor stage.Operating it exactly at series resonance (Fig. 21-5b)....
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The circuit shown in the chart is 1kHz sine wave oscillator circuit. Basing on the double-T circuit, the circuit using 741ordinary operational amplifier to produce 1000Hz sine wave output. Adjusting 100k? potentiometer will make circuit start oscillation,....
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The circuit includes two synchronized multivibrators which are composed ofone pair of 555time base circuits. The circuit can output two synchronized pulse signals,and the spacing and frequency can be changed by adjusting the time constant. The circuit is....
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This circuit is basically simple and easy to build, it uses two transistors as active components and a few passive components like resistors, capacitors and two LEDs. The circuit makes use of the MPS2222 transistor. You can use any NPN type transistor as the....
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The two parts` component parameters and models of the circuit are corresponding to simultaneously obtain a rectangular wave with duty ratio of 1:1, its frequency f = 0.7/RB ¢ C. RB is Rb1 or Rb2 in the figure, and its upper limit value Rb1 < 0.5?RC1 ; Rb2 <....
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Crystal oscillator works as 51MHz crystal( the third harmonic of 17MHz). According to the different structures, the drain - gate capacitance can be selected between 0.5 to 1.8 pF. L2`s turns are about 20% of the L1. 470 ? source resistor can change the....
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This oscillator uses a very large capacitance-to-inductance ratio. L1 is a one-tum coil consisting of a loop of #12 wire 12 in diameter. This circuit is useful for metal detectors, etc., where a loop antenna is used....
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The oscillator uses a fundamental quartz crystal, and the oscillation frequency can be up to 10MHz. Oscillator circuit is tuned to the resonant frequency. Capacitor C requires below 4.7pF, and it is connected to a follower to isolate the quartz crystal....
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Many RC oscillators use advanced circuit in phase shift unit. It uses a voltage feedback amplifier, of which the gain will get a sharp decline in a higher frequency and stop oscillation before reaching the desired frequency. That is the reason why voltage....
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Low-drift solid-state design for 40-meter band has maximum change of only 25 Hz from cold start to full warm-up at 25?. After stabilization, maximum hunting is 5 Hz. Drift is minimized by paralleling two or more capacitors in critical parts of circuit.....
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The NC monostable multivibrator circuit shown in the chart is composed of four 2 input NOR gate CC4001 and 14-bit binary serial counter / divider CC4020. It mainly used as time delay switch or timer in automatic control equipments....
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The circuit is composed of lag comparator with A1 and inverting integrator A2, and the charging and discharging time constant is decided by integral resistors (R1+RP1) and the capacitor C1. VD1~VD5 form the limiter circuit. The maximum oscillation frequency....
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The JFET Pierce oscillator is stable and simple. It can be the clock of a microprocessor, a digital timepiece or a calculator. With a probe at the output, it can be used as a precise injection oscillator for troubleshooting. Attach a small length of wire at....
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As shown in the figure, 555, Rl, RPland C1form thecontrolled audio oscillator, f = 1.44 / ( R1 +2 RP1) C1, the icon parameter frequency isbetween 600Hz ~ 20kHz, and it can beselected by adjusting RP1....
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A 2N366 is configured as an audio feedback oscillator using an audio transformer is shown. Adjust R1 for proper operation and desired audio note....
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The Colpitts Oscillator is characterised by tapping the mid-point of the capacitive side of the oscillator section. The inductor can be the primary side of a speaker transformer. The feedback comes via the inductor....
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Figure shows the Colpitts oscillator circuit. It has a base frequency crystal, and the frequency is 1499 kHz, crystal SJT is connected to the both ends of capacitor C2, C3. Emitter divider resistor R2, R3 provide basic feedback signal, the feedback voltage....
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This circuit is the improved hartley oscillator circuit, changing the base current can adjust the frequency in a given range. The output signal amplitude is higher than 6V in 6k? load resistance,and it is suitable for electronic cello circuits....
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PLL synthesizer oscillator circuit is a feedback loop composed of reference oscillator, phase comparator, loop filter, voltage controlled oscillator, programmable frequency divider and other components. In the circuit, the reference oscillator uses a crystal....
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Figure (a) and (b) show the two 2MHZ basic oscillator circuits. According to the circuit structure, it can adjust its best operating point by testing....
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Fig a shows a multivibrator circuit which can generate square wave signal; Figure b is a flip-flop circuit which uses the under edge of the input signal to generate a trigger pulse signal. Figure c is a monostable circuit which can be used for waveform....
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As shown in Figure 16-4, a CD4017 is connected as senary counter, and the input clock is 300Hz.VD1 ~ VD9, R1 ~ R3 form the three three-input OR gates, which can respectively get two 50Hz three-phase wave signal with 120 degrees phase difference. A, B, C can....
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The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and....
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The chart shows the Wien bridge sine wave oscillator circuit. The amount of negative feedback circuit is determined by the internal resistance of FET. When the peak value of oscillator output reaches the regulated voltage of regulator diode D1, Q2 turns on,....
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This is a PLL controller that works with the VCO/Modulator that I designed. Use these two modules together for a complete baseband-capable exciter unit. This PLL controller features a rock-stable crystal controlled reference, in conjunction with a....
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Here`s a PLL FM Transmitter using LMX1601, ATtiny2313 or AT90S2313 microcontrollers. The common characteristic of all of the previous low power FM transmitters I`ve built over the decades, is that their operating frequency is determined by an LC resonant....
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The circuit shown here is of a good Stereo FM transmitter that can transmit high quality signals up to a range of 70 feet. The circuit is based on BH1417 PLL stereo transmitter IC from Rhom semiconductors. The IC has separate audio processing sections for....
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The remote control electric hoist control circuit consists of the wireless transmitter, wireless receiver control circuit and the main control circuit. Wireless transmitter uses TWH9326 four key BP transmitter. Wireless receiver control circuit consists of....
The remote control robot circuit is as shown in the figure. The figure 2-36(a) is the circuit diagram, the figure 2-36(b) is the operating timing diagram. The rotation process of the rebot is: in the circuit, the ultrasonic launching circuit is composed of....
The SC41343 is designed as one kind of infrared, ultrasonic or RF remote control launch coding circuit. The internal circuit is composed of the sequence generator, control logic circuit?4-bit shift register?data extraction circuit and the latch circuit.....
The SL517 is designed as the audio, RF or infrared decoder circuit that can be used in the electronic toy application. The internal circuit is composed of the analog amplifier, the frequency divider, the bistable circuit and the driver. Features It uses the....
When the current is less than the value set, the bias current provided by R1 leads the P3 to be saturated to conduct. And it can not afford to control the current. When the current is greater than or equal to the set value, the pressure drop on R would....
In this figure S1 can start timing and when the timer starts, turning this switch has no effect.S2 is the OFF switch in the middle and turning this switch can make the timer complete the procedure: charging-open circuit-discharging. Because of charging....
In the figure is the FM modulation circuit of crystal oscillator. FM modulation has direct and indirect FM ways, the direct FM method is to directly change the frequency of the oscillating circuit, it`s simple, but as it is the LC oscillating circuit, the....
See as the figure, the controller consists of liquid level, trigger controller and step-down rectifier circuit, etc. The water level detecting poles of a, b and c compose the bias circuit as the water level detector with W1, R1, R2 and R3. When the water....
Is an eight-way signal remote control selection circuit composed of ZHJ-9904 ; (B) is remote control transmitter circuit; (C) is the eight-way switch control circuit; (D) is remote control transmitter...
This is the electric thermometer circuit composed of LM134. In the circuit, the voltage or current output by LM134 is in proportion to the thermodynamics temperature, which can be read out on the 100?A meter, the test temperature range of the meter is....
The switch shut off time delay circuit is shown as below. The switch shut off time delay circuit is composed of the timer, optocouplers, bridge SCR, SCR AC switch. When the control button is released, the keeping motor or other AC start power for 1 hour.....
When this thermometer is used in the room, it can work in the intermittent way, and this working state can be kept in the temperature test circuit, because internal temperature doesn`t change sharply. The astable multi-resonance oscillator consists of VT1....
It can set delay time according to the voltage Us and resistor R. In the circuit, S1 is the the discharge switch of capacitor C. When the switch S1 is closed, the stored charge on C will be released through S1 to ensure the accuracy of the delay time the....
Wireless remote control transmitter circuit is composed of control buttons S1 ~ S16, resistors R1 ~ R3, capacitor C1 regulator diode VS, crystal oscillator BC1, DTMF encoder IC IC1 and IC2 wireless remote control transmitter integrated circuit components. It....
This wide-range light dimmer circuit uses a unijunction transistor and a pulse transformer to provide phase control for the TRIAC. The circuit operates from a 115 volt, 60 Hz source and can control up to 800 watts of power to incandescent tights. The power....
741 opamp is connected as audio oscillator with Radio Shack 276-677 photocells in feedback circuits. When light strikes PC1, its resistance decreases and frequency of audio tone in headphone decreases correspondingly. When light strikes PC2, which is....
This circuit is composed of the light measurement circuit and the flash circuit, as the figure shows. It can be used in the POPTICS (one kind of popular integration camera), the Franka X-500 and the WIZEN-860S cameras. It is composed of the following....
The temperature measuring range of this electronic thermometer is 0-50?, the precision is 0.1?, the measurement results are intuitively displayed by digital display. This electronic thermometer circuit is composed of temperature detection circuit, monostable....
Pyroelectric infrared sensor head is same with the figure. When it detects the human body infrared signal in guarding zone, the sensor head will output a positive jump pulse signal, this signal is added to input terminal P point. IC1 adopts 555 time base....
In the silicon-controlled trigger circuit, cadmium sulfide cell connects the relaxation oscillator before having a sensor to blink in darkroom. That make the speaker emit the warning sound of Ka, Li. The rate of the sound will increase with the quantity of....
This DIY magnetic field sensor circuit is very simple and can detect fixed magnetic fields or fields that are varying at an audio frequency. The unit is not intended to provide accurate measurement of magnetic field strength. A small and not very powerfull....
The circuit is formed by light metering circuit and flash circuit,just as shown in picture.It is suitable for POPTICS (a popular integrated camera), Franka X-500, WIZEN-860S and so on.It consists of the following circuit:(1)VT1,VT2,light metering device RG....
This circuit includes micro vibration sensor, trigger delay circuit and control circuit, the figure is as shown. The micro vibration sensor contains vibration sensor device and high power amplifier circuit, it can induce very weak external vibration signal,....
The LM35 temperature sensor provides an output of 10 mV/ƒ for every degree Celsius over 0ƒ. At 20ƒ the output voltage is 20 x 10 = 200 mV. The circuit consurnes 60 A. The load resistance should not be less than 5 k ©. A 4- to 20-V supply can be used. (View)....
This is a luminous flux test circuit with optical resistors. In the circuit, the optical resistor RG forms a bridge with RP1,RP2,R1 and R2; RP1 is used to adjust the balance of the bridge; RP2 is used to adjust the sensitivity of the circuit. If we adjust....
The figure is a schematic circuit of UV sensor. When UV sensor is coupled by voltage between the cathode and anode, and the UV radiation gets through the quartz glass tube on the cathode of the optical surface, because of the cathode material coated with....
To use the circuit you will need a wind vane like the one shown. It should have a weighted front end and an air paddle in the rear. Attach a small, strong magnet to the front part of the wind-vane arm. Then, position eight reed magnetic switches in a circle....
The circuit SJT is a 1024kHz warming crystal oscillator. Circuit is shown as the chart. As its output signal level is low, so the following transistor VTl is used as the buffer amplifier. The base bias resistor R2 of VTl, the load resistor R3, the emitter....
The oscillator circuit which is composed of the 1MHz quartz crystal resonator and the NAND gate is as shown in the figure, the NAND gate 3 is the output buffer stage. This circuit can be used to calibrate the standard frequency. Figure 1 The 1MHz quartz....
A 27MHz NBFM transmitter circuit schematic with MC2833 and 2 FET transistors MPF6660. Using a Motorola MC2833 one-chip FM transmitter, a few support components and am MPF6660 RF amp, this transmitter delivers up to 3W into a 50 ? antenna. It is capable of....
The 27MHz quartz crystal oscillator circuit is as shown in figure 1. The biasing circuit is composed of the R1, R2 and R3, C6 is the bypass capacitor. The partial voltage circuit is composed of the C1, C2, C3 and C4 to control the strength of oscillation. L1....
As the figure 14-17 shows, this circuit is composed of the input circuit, the line frequency synchronization generator, the sample-and-hold circuit, the voltage control delay generator and the RF modulator.The input circuit is composed of the input....
As the figure 14-41 shows, the multivibrator is composed of the 555 and some capacitance resistance components, the oscillation frequency depends on the values of Ra, R16 and C3. f=1.44/(Ra+2R16)C3, the Ra of the formula corresponds to the different values....
The electronic switch is composed of the CK-4 type magnetic control switch and the VT1?R1?R2. When the bathroom door closes, the permanent magnet ZT and the reed pipe GA get close to separate the two touch tablets of GA, VT1 cuts off, pin-2 of IC has the....
As shown in Figure it is 567 FM demodulation circuit. In the figue, the FM signalenters from the 3 foot, the demodulated signal goes out from 5 foot. FM signal center frequency which the circuit can demodulateis: fo = 1.1 / RC, C1 isfilter capacitor, and C2....
Using an EXAR XR2206, this generator will produce sine, square, and triangular waves from Hz to 100 kHz. U1 is the XR2206 chip, R7 controls frequency, and 55 through 58 select the frequency range. U3 produces a TTL-compatible square-wave output, while U3C....
Combines signals from loop and sense antennas of automatic direction finder, to give 130-cps output having correct phase for driving rotor of resolver to null position.-P. V.Sparks, Servo Filter and Gain Control lmprove Automatic Direction Finder,....
Here`s BH1417 USB FM Transmitter with built-in PLL circuit. Its low-frequency signal is converted into high-frequency, which can take any audio device with FM radio (stereo, car CD, MP3, DVD player, etc.), as a normal radio station. Transmitter power is....
When low/high input is voltage in binary form, as obtained from converter circuit (also given in artide) fed by digital voltmeter, circuit produces Iow pitch for binary 0 and high pitch for binary 1 when S2 is set at D for digital voltmeter mode. Recognition....
This is a simple video transmitter that can transmit as far as 50 meters. This video transmitter can be used with the camera or other video sources. You can view them on VHF channel analog TV. Supply voltage to the video transmitter can use 9V battery.....
The RF oscillator using the inverter N2 and 10.7Mhz ceramic filter is driving the parallel combination of N4 to N6 through N3.Since these inverters are in parallel the output impedance will be low so that it can directly drive an aerial of 1/4th wavelength.....
Circuit`s Functions The frequency modulation FM transmitter which can be used in 76~90MHZ FM radio band, usually also it is called wireless microphone.It adopts signals via FM radio receiver.The signals can be transmitted in wireless means if we don`t use....
Here`s simple FM transmitter circuit using medium power 2N2218 transistor. Micropohone is of electret type that connects to two input terminals and the antenna should be a copper wire from 15 to 40 cm. Below is schematic circuit of the fm transmitter....
On frequency stability, the quartz crystal oscillator circuit is very advantageous, even the the VCXO circuit with large amount of frequency changing only changes about 1%, and the linear range of control voltage to frequency variation is not wide. Although....
Frequency signal tracking circuit is the phase-locked loop circuit, which is one of the basic application circuit of CD4046. The circuit shown as the chart and composed of CD4046 is a PLL circuit, and it can capture and track the input signal with the input....
Internal telephone circuit is shown as below,improving slightly a toy telephone will become a variable practical internal telephone. This phone is compose of the phone component,decoding circuit,ringing circuit and other components. Using more than two the....
Telephone electronic coded lock circuit is shown as above,the electronic coded lock is suitable for double audio circuits.After the phone adds this coded lock, when you call out,you must use the buttons on the phone to press the four pre-programmed....
Telephone electronic ringer circuit is shown as above,Figure (a) is the electronic ring circuit with an NPN transistor V1 (choose 9014 or 3DG12) as the core, sound devices YD is also feedback devices composed of the feedback pole and the buzzer equipped with....
The chart shows a function generator circuit composed of 555 timer. The circuit consists of a CH7555 timer and some transistors and RC components. It can generate triangle wave, square wave, sine wave, sawtooth and square wave sweep simultaneously. Ramp can....
This high voltage generator can generate stable high voltage above 8kV. Its circuit is simple. It is stable and reliable. This circuit includes step-down rectifier, voltage regulator circuit, 18kHz multivibrator type oscillator and booster transformer, etc.....
Square-wave generator with LC circuit can get a better frequency stability, it`s as shown in the chart. This three-terminal oscillator of capacitor can be used to generate a square wave, but an operational amplifier is used as the active component....
The linear charging ramp is most useful where linear control of voltage is required.Some possible applications are a long period voltage controlled timer, a voltage to pulse width converter, or a linear pulse width modulator. Q1 is the current source....
In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a....
FM Transmitter is very simple, compact, and has transmission signal with a range of 100-150m, good sensitivity and low current consumption. Transmitter`s schematic consists of a bass amplifier for the first transistor and the proper frequency generator in....
This circuit SJT is 1024kHz temperature compensation crystal oscillator. Circuit theoryis asshown. Because output signal level of the circuit is low, the buffer of follow-up transistor VTl is amplified. VTl base bias resistor R2, the load resistor R3, the....
Simple network design is a key feature of the Pierce circuit, as these 1-MHz oscillators illustrate.Operating the crystal slightly above resonance (Fig.21-5a) requires only one high-gain transistor stage.Operating it exactly at series resonance (Fig. 21-5b)....
The circuit shown in the chart is 1kHz sine wave oscillator circuit. Basing on the double-T circuit, the circuit using 741ordinary operational amplifier to produce 1000Hz sine wave output. Adjusting 100k? potentiometer will make circuit start oscillation,....
The circuit includes two synchronized multivibrators which are composed ofone pair of 555time base circuits. The circuit can output two synchronized pulse signals,and the spacing and frequency can be changed by adjusting the time constant. The circuit is....
This circuit is basically simple and easy to build, it uses two transistors as active components and a few passive components like resistors, capacitors and two LEDs. The circuit makes use of the MPS2222 transistor. You can use any NPN type transistor as the....
The two parts` component parameters and models of the circuit are corresponding to simultaneously obtain a rectangular wave with duty ratio of 1:1, its frequency f = 0.7/RB ¢ C. RB is Rb1 or Rb2 in the figure, and its upper limit value Rb1 < 0.5?RC1 ; Rb2 <....
Crystal oscillator works as 51MHz crystal( the third harmonic of 17MHz). According to the different structures, the drain - gate capacitance can be selected between 0.5 to 1.8 pF. L2`s turns are about 20% of the L1. 470 ? source resistor can change the....
This oscillator uses a very large capacitance-to-inductance ratio. L1 is a one-tum coil consisting of a loop of #12 wire 12 in diameter. This circuit is useful for metal detectors, etc., where a loop antenna is used....
The oscillator uses a fundamental quartz crystal, and the oscillation frequency can be up to 10MHz. Oscillator circuit is tuned to the resonant frequency. Capacitor C requires below 4.7pF, and it is connected to a follower to isolate the quartz crystal....
Many RC oscillators use advanced circuit in phase shift unit. It uses a voltage feedback amplifier, of which the gain will get a sharp decline in a higher frequency and stop oscillation before reaching the desired frequency. That is the reason why voltage....
Low-drift solid-state design for 40-meter band has maximum change of only 25 Hz from cold start to full warm-up at 25?. After stabilization, maximum hunting is 5 Hz. Drift is minimized by paralleling two or more capacitors in critical parts of circuit.....
The NC monostable multivibrator circuit shown in the chart is composed of four 2 input NOR gate CC4001 and 14-bit binary serial counter / divider CC4020. It mainly used as time delay switch or timer in automatic control equipments....
The circuit is composed of lag comparator with A1 and inverting integrator A2, and the charging and discharging time constant is decided by integral resistors (R1+RP1) and the capacitor C1. VD1~VD5 form the limiter circuit. The maximum oscillation frequency....
The JFET Pierce oscillator is stable and simple. It can be the clock of a microprocessor, a digital timepiece or a calculator. With a probe at the output, it can be used as a precise injection oscillator for troubleshooting. Attach a small length of wire at....
As shown in the figure, 555, Rl, RPland C1form thecontrolled audio oscillator, f = 1.44 / ( R1 +2 RP1) C1, the icon parameter frequency isbetween 600Hz ~ 20kHz, and it can beselected by adjusting RP1....
A 2N366 is configured as an audio feedback oscillator using an audio transformer is shown. Adjust R1 for proper operation and desired audio note....
The Colpitts Oscillator is characterised by tapping the mid-point of the capacitive side of the oscillator section. The inductor can be the primary side of a speaker transformer. The feedback comes via the inductor....
Figure shows the Colpitts oscillator circuit. It has a base frequency crystal, and the frequency is 1499 kHz, crystal SJT is connected to the both ends of capacitor C2, C3. Emitter divider resistor R2, R3 provide basic feedback signal, the feedback voltage....
This circuit is the improved hartley oscillator circuit, changing the base current can adjust the frequency in a given range. The output signal amplitude is higher than 6V in 6k? load resistance,and it is suitable for electronic cello circuits....
PLL synthesizer oscillator circuit is a feedback loop composed of reference oscillator, phase comparator, loop filter, voltage controlled oscillator, programmable frequency divider and other components. In the circuit, the reference oscillator uses a crystal....
Figure (a) and (b) show the two 2MHZ basic oscillator circuits. According to the circuit structure, it can adjust its best operating point by testing....
Fig a shows a multivibrator circuit which can generate square wave signal; Figure b is a flip-flop circuit which uses the under edge of the input signal to generate a trigger pulse signal. Figure c is a monostable circuit which can be used for waveform....
As shown in Figure 16-4, a CD4017 is connected as senary counter, and the input clock is 300Hz.VD1 ~ VD9, R1 ~ R3 form the three three-input OR gates, which can respectively get two 50Hz three-phase wave signal with 120 degrees phase difference. A, B, C can....
The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and....
The chart shows the Wien bridge sine wave oscillator circuit. The amount of negative feedback circuit is determined by the internal resistance of FET. When the peak value of oscillator output reaches the regulated voltage of regulator diode D1, Q2 turns on,....
This is a PLL controller that works with the VCO/Modulator that I designed. Use these two modules together for a complete baseband-capable exciter unit. This PLL controller features a rock-stable crystal controlled reference, in conjunction with a....
Here`s a PLL FM Transmitter using LMX1601, ATtiny2313 or AT90S2313 microcontrollers. The common characteristic of all of the previous low power FM transmitters I`ve built over the decades, is that their operating frequency is determined by an LC resonant....
The circuit shown here is of a good Stereo FM transmitter that can transmit high quality signals up to a range of 70 feet. The circuit is based on BH1417 PLL stereo transmitter IC from Rhom semiconductors. The IC has separate audio processing sections for....
