An audio source, like a mixer, preamp, EQ, or a recorder, is fed to the input of the Electronic Crossover Circuit. This signal is either AC or coupling, depending on the setting of switch 51, the non-inverting input of buffer amplifier Ul-a, a section of a quad BIFET, low amp TL074 noise made by Texas Instruments op. This stage has a gain of 2, and its output is distributed to both a low pass filter made by R4, R5, C2, C3, and Uld op-amp, and a high-pass filter made by R6,.....
A flashing light of high brightness and short duty cycle is often desired to provide maximum visibility and battery life. This necessitates using an output transistor, which can supply the cold filament surge current of the lamp while maintaining a low saturation voltage. ..
This converter uses a low-pass filter instead of the usual tuned circuit so the only tuning required is with the receiver. The dual-gate MOSFET and FET used in the mixer and oscillator aren"t critical. Any crystal having a frequency compatible with the receiver tuning range may be used. For example, with a 3500 kHz crystal, 3500 kHz on the receiver dial corresponds to zero kHz; 3600 to 100 kHz; 3700 to 200 kHz, etc..
A phase-controlled dimmer delays the triac turn-on to a selected point in each successive ac half cycle. Use this circuit only for incandescent lamps, heaters, soldering irons,..
This low-power video transmitter is useful for R/C applications, surveillance, or amateur radio applications. Seven transistors are used in a crystal oscillator-multiplier RF power amplifier chain, and a high-level video modulator. A 9- to 14-Vdc supply is required. ..
The step size of the converter is variable by selection of the high order data bits. The first DAC, A, has a stable reference current supplied via the 10.24 V reference IC and Rl. R2 provides bias cancellation. As shown, only the first 4 MSB inputs are used, giving a step size of 225/256 2.048/16 = 0.127 mA. This current supplies the reference for DAC whose step size is then 0.1275/256 = 0.498 µ. Complementary voltage outputs are available for unipolar output and.....
This inexpensive, easy to construct amplifier uses two MRF454 devices..
A high-gain amplifier using a UA741 is used to sense relative voltage drop in a conductor, and therefore current i..
In this circuit, audio fed to the control channel is amplified and rectified by Dl and D2. This dc level activates LED D3 via Q2. The light from D3 causes R9, a light-dependent resistor to decrease resistance. As Rll (audio gain) is set higher, more audio is present at the output of Ql. Audio fed into J2 is shunted to ground via R9 and less of this audio appears at J3...
This circuit uses a stereo amplifier IC in a 14-pin DIL package that requires very few external components to make a complete 2 Watt per channel power amplifier. ..
The circuit consists of two basic circuits, the oscillator and the detector. The oscillator uses an FET in a Colpitts configuration. The energy circulating in the oscillator tank is coupled through C4 to the detector circuit, where a small diode (D2) rectifies it, feeding a dc voltage to the Darlington pair (Q2, A3) controlled by the sensitivity control (R3). Any small variations in the bias of the amplifier will cause large variations of current through the LED indicator.....
Assume the correct phase sequence to be VA-VB-VC. The circuit terminals are connected such that Tl gets connected to phase A and T2 to phase B. The capacitor advances the voltage developed across R2 due to phase "B" by — 60°, while the voltages developed across it by phase "A" is in phase with VA as shown in Fig. 69-1. The net voltage developed across R2 ~ zero, the neon lamp is not energized, thereby signaling correct phase sequence. If terminal T2 gets.....
The input signal is amplified by the transistors. The distorted output is then clipped by the two diodes and the high frequency noise is filtered from the circuit via the 500 pF capacitor..
If we are speaking about professional Cell phone Jammers we are talking about this schematic below. First off all you should be very careful how to use this device. Its fully illegal and so the purpose I post this Circuit is only for educational and testing reasons. This type of device is being used by security for VIPS, specially at their limousines to avoid bomb triggering while the car passes from the target cell phone-bomb. Offcourse there are those who use it to make.....
Ql and Q2 constitute a simple, high-speed FET input buffer. Ql functions as a source follower, with the Q2 current source load setting the drain-source channel current. The LT1010 buffer provides output drive capability for cables or whatever load is required. Normally, this open-loop configuration would be quite drifty because there is no de feedback. The LTC1052 contributes this function to stabilize the circuit. It does this by comparing the filtered circuit output.....
The problem with using two zeners back to back in series to get symmetrical clamping is that the knee of the..
A circuit for multiplying the width of incoming pulses by a factor greater or less than unity is simple to build and has the feature that the multiplying factor can be selected by adjusting one potentiometer only. The multiplying factor is determined by setting the potentiometer in the feedback of a 741 amplifier. The input pulses of width r and repetition period is used to trigger a sawtooth generator at its rising edges to produce the waveform e2 having a peak value of.....
Inserting two 1-MO resistors, R1 and R2, in the output stage of one of the circuit"s inverters limits the current needed by the oscillator tone more than a few pA. This circuit includes a CD4007 package, which has three CMOS inverters. It forms a standard three-inverter oscillator. Resistors R1 and R2, in series with separate drains on inverter pins 8 and 13, limit the oscillator"s supply current. Capacitor C1 and resistors R5 set the off time of the oscillator, C1; R6.....
Using an ionization chamber and a high-impedance (CA3130) op amp, the presence of smoke will cause the CA3130 ..
The circuit is built around a 741 general-purpose op amp that is configured as a voltage follower; with the components shown, the op amp has a voltage gain of one. The output of the 741 is used to drive a 50- meter movement. Potentiometer R7 is used to zero the meter and R6 sets the meter`s full-scale reading, Calibrating the meter is a snap. With no input applied to the circuit, set R6 to mid-position and adjust R7 to zero the meter. Once that is done, apply a positive.....
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