Free Simple Circuit Diagram
The idea of a color organ is that any sound, including musical sound, can be transformed into light. As stated by wave theory, both music and light have similar properties: frequency. Any note, or combination of notes (chord) can be then mapped to a color. A low frequency sound can be associated to red or near infrared, and high frequency […]
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This is a schematic diagram of general-purpose audio frequency (AF) amplifier circuit. This circuit uses cheap 1/4-W resistors, no high precision needed so 5%-tolerance of carbon or metal film units is good enough. This circuit has frequency response range from 16Hz to 30kHz. This amplifier also accepts standard automotive battery supply voltage range: 12 to 14 V. The gain of […]
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This is a Wien-bridge sine-wave oscillator circuit. This circuit uses negative-feedback stabilization to make sure the gain won’t go higher than unity to prevent signal distortion. The D2 and D1 will conduct when Negative peaks in excess of -8.5 V. That action will charges C4. The amplifier gain is determined by the biased Q1 that is charged by C4. Offset […]
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The schematic diagram below shows a variable 0-180 degree phase shifter circuit. This circuit can provide phase shifted output (compared with the input) between 0 and 180 degrees for frequencies up to 3MHz with same amplitude (unity gain or gain=1.) This circuit uses inexpensive NPN transistor, 2N3904, but almost any small signal transistor type can be used. Using R5 and […]
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