Free Simple Circuit Diagram
The output of this circuit is push-pull and consumes less than 3mA (with no signal) but drives the earpiece to a very loud level when audio is detected. Because the whole circuit is Dc coupled, its extremely difficult to set up. Basically you don’t know where to start with the biasing. 8k2 between the emitter of the first transistor and […]
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Circuit below is a very sensitive 3-transistor amplifier using a speaker transformer. This can be wound on a short length of ferrite rod as show above or 150 turns on a 10mH choke. The biasing of the middle transistor is set for 3 V supply. During idle conditions and the quiescent current is just 5mA, the second and third transistors […]
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The circuit diagram below shows a circuit of graphic equalizer 6 band of regulation. The potentiometer RV1-6 regulates each band, and the sliding type is the recommended for better visual indication. . The gain is null (flat) in the center position of potentiometer, but in the maximum and minimum position has +/- 15 dB, boost or cutting off, respectively. It […]
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Below is a classic circuit of regulation of tone of three way. With this circuit, we can regulate low, mid and high frequencies of acoustic signal. We can regulate the boost/cut in the range of +- 18 dB/oct. The supply on the the circuit is 15V, but it can be supplied with 9 until 30V. It’s enough to connected pin […]
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