Free Circuit Diagram

This is an audio amplifier circuit which has power of 18W. It is very simple but it has a high quality. This circuit does not require pre amplifier. It can be directly connected to tuners, tape recorders, and CD players. It produces 18 Watt RMS into 8 Ohm (1KHz sine wave) output.this circuit has a [...]

Electroscope is a device that is used to detect electrostatic charges. Operation: To reduce AC noise this circuit uses C1, but it will lower the sensitivity a bit. As a voltage divider we use the MPF102 and R1. The divider’s output will be about 4.5V diving a half-scale reading on M1, a 200-uA [...]

This audio power amplifier circuit is simple and robust, and use discrete component available on many electronic part stores. The final transistors use 2N3055 and MJE2055. Here is the circuit’s schematic diagram: The MJE2055 is an npn transistor, but the configuration with TIP42A make the whole combination of TIP42A and MJE2055 are seen [...]

Using only a single chip and few passive components, you can build 8-14 Watt audio power amplifier using TDA2030 chip. Here is the circuit schematic diagram: If you use 4 ohm speaker then you get 14 Watt output power, and around 8 Watt if you use 8 ohm loudspeaker. Make sure the [...]

Metal Detector Circuit Topology One of the simplest method of metal detecting is by beat frequency oscillator. Basically, the circuit consist of two balanced oscillator. One oscillator provides the reference signal, and other oscillator is acting as the detector element. The reference oscillator’s frequency is fix, while the detector oscillator is variable depending on [...]

Precision accelerometers needs inverting mode amplifier since they are usually charge-output  devices. This amplifier convert charges into voltage output. The circuit below is an example of accelerometer with DC servo. The charge from the transducer is converted to a voltage by C1, which should equal the transducer capacitance plus the input capacitance of [...]