Free electronic circuit design and schematic diagram
This FSK demodulator convert the FSK signal to serial digital signal. FSK modulation is used to transmit digital serial data, and we need to demodulate it to get back the digital data at the receiver. Here is the schematic diagram of the circuit: This demodulator circuit uses 2225/2025 Hz for mark/space coding, and this frequency is the answering frequency of […]
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This circuit enables you to connect your camera with very long wire. The circuit is actually a video amplifiers. At the sender part, the amplifier is used to make a stronger signal. This stronger video signal then can be transmitted through the long cables. The signal is transmitted using balanced mode, where two wires are driven in the opposite phase. […]
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This constant current constant voltage SMPS can be used to efficiently charge a battery. This circuit gives 7.2V at constant voltage mode, and 600 mA at constant current mode. Here is the schematic diagram of the circuit: The mechanism is simple, when the load impedance is high, then the output voltage will be constant at 7.2V. When the load impedance […]
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High voltage current sensing/monitoring can be designed using LTC6101 op-amp. The following current sensing circuit is capable of measuring electrical current in 500 volts system. Here is the schematic diagram of the circuit: Two external Mosfets is added to hold off the voltage, allows the LTC6101 to be connected to a very high potentials and measure the current flow. The […]
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Active power factor correction stabilize the electrical demand of a device to give the best power factor characteristic of many types of loads. To meet power factor regulation, a low cost solution should be designed. In many application, the need of high DC voltage is usually implemented by a direct rectification of the AC line followed by bulk capacitor filtering. […]
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This battery charger circuit use a flyback converter topology, and implements a current-limited power supply to charge lead-acid batteries. Here is the schematic diagram of the charger circuit: The flyback transformer provide isolation and voltage input range flexibility, event at supply voltage lower that the battery voltage. Monitoring the charging current is done by sensing the output using MAX471 current […]
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It would be cool and elegant to a have mechanical sound character for our electronic metronome. This electronic metronome circuit will produce such sound, making your life more fun. Here is schematic diagram of the circuit: The metronome circuit consists of two 555 oscillators. The first oscillator is used to make high frequency tone, and the second one is used […]
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