Free electronic circuit design and schematic diagram
This is a TC9400 Frequency-to-Voltage Converter circuit. Beside used as voltage to frequency converter, the TC9400 can also used as Frequency-to-Voltage Converter. The TC9400 will convert the input frequency waveform to output voltage linearly. This circuit has a threshold detector’s input that is used to detect each zero. The zero will cause a precise amount of charge(q=Cref Vref) to be […]
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This is a TC9400 10Hz to 10kHz Voltage-to-Frequency Converter circuit. This ciruit uses TC9400 to convert voltage to frequency. The TC9400 uses charge balancing principal. This circuit uses input resistor to convert the input voltage to input current. Then the capacitor will change the current into charge which will decrease the Op amp output voltage linearly. This circuit also featured […]
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This is a Mini MW (Medium Wave) Transmitter circuit. This circuit consist of combination of transistors SA103 and SA101. Those transistors is used as oscillator and modulation signal amplifier. Here is the schematic diagram of the circuit: The transistor is of germanium type, but I think you can replace it with silicon type from the high frequency one. The inductors […]
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This is a Stereo VU Booster circuit. In this circuit, shown in the schematic diagram, transistor FCS9014 is used. Actually you can use almost any type of small signal NPN transistor. This transistor usually used for regulator and pre-amp circuit. Here is the schematic diagram of the circuit: The schematic diagram show only one channel, so you have to build […]
Read moreThe wiring diagram is important to troubleshoot the problem in the car. This video explains how to use wiring diagram to fix a problem. The wiring diagram contain the information of wiring path of the application in the car like heater, AC, Tachometer and so on. First, the wiring diagram must be fotocopied. Then give the highlight where the problem […]
Read moreThis is a video about how to tell if the car is positive or negative ground. This video explains step by step how to detect the positive or negative ground. To know the ground of the car is very important to determine where the application is wired. To detect the ground of the car is easy, it use the battery […]
Read moreThis is a video about bad ground. This video explain how to test the bad ground. The bad ground can cause reduce the light of the lamp. To test the bad ground is easy just need a couple of jumper wire. The one of the jumper wire is connected to the good ground and the other is connected to the […]
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