Free Simple Circuit Diagram
This AM radio circuit is a low power transmitter working on broadcast band. The simplicity is implemented using a single-transistor amplifier stage, and for the stability a crystal is used to excite the 670Hz oscillation. The output power of this AM transmitter circuit is 400 micro watts for antenna. L1 and L3 is 40-300 uH ferrite core antenna. Here is […]
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VCO (voltage controlled oscillator) is an electronic signal generator which produce a signal that has variable frequency depends on a voltage level at its control input. Many VCO circuits are based on ramp generator to produce a variable frequency output, but they produce a square wave signal. With varactor (voltage controlled variable capacitor), we can produce a high quality sine […]
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Video switch is required to mux/multiplex several video sources, enable multiple camera to be displayed subsequently on a single monitor. This multiplexing could significantly reduce the cost and the space for the monitor. High off isolation means that the signal path from input to output will be completely disconnected, ensuring there will be no signal leakage and cross-talk between channels. […]
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This is a circuit of 90-125 MHz Crystal which is very useful for VHF/UHF converters. This circuit provide 5 to 15 mW output. High-quality fifth- or seventh-over-tone crystal type can be used in this circuit. Undesired oscillation never reach above 500 MHz because of Ferrite bead FB. Using regulated power supply and allowing crystal to operate at its natural series-resonant […]
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