Free Simple Circuit Diagram
With LM1875, we can build a low cost but high performance audio power amplifier. With 50V power supply, it can produce 20W output power for 4 or 8 ohm speaker. We can even get 30W output if we use 60V and 8 ohm speaker. Here is the schematic diagram of the circuit: This integrated circuit audio power amplifier has very […]
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Metronome circuit is a much cheaper option compared to old mechanical metronome. With only few electronic components, we can build a low cost metronome. Here is the schematic diagram of the circuit: You can build it with veroboard, matrix board, or even with no board at all: just solder each component leads and cables directly. If you build without board, […]
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Using very popular multivibrator 555 IC, we can build an alarm circuit which is similar to old ambulance siren. There are two sections inside the circuit, first is a low frequency oscillator for two level frequency modulation, and the second is the higher frequency oscillator for sound generation. Here is the schematic diagram of the circuit: The upper part is […]
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This timer circuit use a single op-amp which is configured as comparator, very simple, and cheap. This alarm will sound a buzzer after a period of time has elapsed since the power supply is applied. Here is the schematic diagram of the circuit: At the initial condition after the circuit is powered (you better insert a switch fro easy operation), […]
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