Free electronic circuit design and schematic diagram
A varactor is also known as a varicap or a variable capacitance diode. An electrically controllable capacitance is provided by this varactor which can be used in tuned circuits. What makes it’s advantageous in many application are the small size and inexpensive. If compared to a manually controlled variable capacitor, this varactor has disadvantages such as lower Q, nonlinearity, lower […]
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This voltage to frequency converter (VFC) circuit uses 555 IC and 741 op-amp as the main components. Up to 20kHz oscillation can be produced by this circuit. Here is the schematic diagram: The zero adjustment is used to adjust the lowest frequency, short the input to ground and adjust this pot to obtain the lowest frequency limit. This circuit uses […]
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Low distortion circuit is very important if we want to measure distortion level of an audio equipment, but this is just one example of low distortion oscillator circuit application. Here is the schematic diagram: This oscillator is designed for audio application, with the adjustable frequency range of 30Hz to 20kHz, set by 470k pot. This potentiometer should be of stereo […]
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A 60Hz signal generator can be useful in testing your circuits. You can test your notch filter, simulating hum noise, or you can use it as part of your DC-to-AC inverter design. Here is the schematic diagram of the circuit: The circuit consist of twin T network built around 33k resistors and 0.068uF caps inside a feedback loop. You can […]
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Phase-locked loop is very common in telecommunication, control, and other electronic application. PLL can be used to demodulate FM signal, produce a stable clock signal, or to recover a synchronization signal from noise. Many single chip integrated circuits (IC) are produced for this PLL system, and LM359 is one of them. This PLL is capable to operate up to 5MHz, […]
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Phase-locked loop is very common in telecommunication, control, and other electronic application. PLL can be used to demodulate FM signal, produce a stable clock signal, or to recover a synchronization signal from noise. Many single chip integrated circuits (IC) are produced for this PLL system, and LM359 is one of them. This PLL is capable to operate up to 5MHz, […]
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Circuit below is circuit of a transistor blocking oscillator. The transformer is phased. This cause any increase in collector current pulls the base up, further increasing the current. The transformer may the the most appropriate but not the most optimum. Any fluctuation in the collector current is fed back and reinforced because the 10k resistor biases the transistor. The base […]
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