Free electronic circuit design and schematic diagram
Quadrature oscillator generate two sine-wave signal, but one signal is shifted 90 degree from the other signal. One output that lead the other called cosine signal, and the other is called sine. Here is the schematic diagram of the circuit: This circuit is another type of pahase shift oscillator, with three phase shifter sections. Each section is configured to produce […]
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This current sensing circuit sense the current at the high side (between positive supply and load). This circuit take the benefit of the microampere supply current and Rail-to-Rail input of the LT1494 op-amp. Here is the schematic diagram of the circuit: Look at the op-amp, the inverting input is connected directly to the output, and this negative feedback will keep […]
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Metronome is very important tool if you studying music playing. There are mechanical metronome device in the past, but today, electronic metronome is much more popular since it can be very simple, compact/small, reliable, and also has the most interesting feature: cheap. Here is one example of the electronic metronome schematic: Parts: C1 1 uF 63V Polyester Capacitor C2 10nF […]
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A phase control circuit can be used to control the power delivered to an AC load. The phase control circuit control the AC waveform, cutting the cycle to give full cycle, half cycle, zero cycle, or somewhere in between. You can say this circuit is similar to a dimmer circuit, but the switching is synchronized with the zero crossing of […]
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This sine wave generator is adjustable between 15 Hz to 150 kHz. The circuit is basically a Wien-bridge oscillator, with multiple capacitor selection. Here is the schematic diagram: A stereo 10k potentiometer is used to control the frequency. The dashed line connecting these two potentiometers show that both potentiometer has single axis.
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This capacitance meter circuit is similar with previous meter circuit, but it uses transistors rather than logic gates. Here is the schematic diagram: You can see the circuit uses pnp transistor, you can use almost any pnp transistors with frequency bandwidth og 100MHz and collecttor current handling capability of 100 mA to replace the transistor if you can find the […]
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The Battery Charger Circuit This lead acid battery charger circuit design is very simple and smart. I call it a smart battery charger design because it uses only few components to support many features. Here is the schematic diagram of the circuit: This circuit is suitable for a general purpose lead acid battery charger, or for a charger modul that […]
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