1W Stereo Audio Amplifier using LM386N

This is 1W stereo audio amplifier with LM386N. The output power is 1 watt for each channel, so it should be use two ICs of LM386N National Semiconductor for stereo channel. This circuit belongs to kitsrus.com and the kit is available there or at electronickits.com. This circuit only need 10mA current with best voltage supply… Read More »

100W Audio Amplifier with Transistor BDW83D/BDW84D

Here is the circuit diagram of 100W audio amplifier which using power transistor BDW83D and BDW84D for the final amplification. It uses dual polarity power supply to work. Copyright belong to Smart Kit. The circuit should be seen like this: This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity,… Read More »

20 Watt Audio Amplifier with LM1875

This is 20 watt audio amplifier circuit design which use IC LM1875 as main component. This circuit is simple and very easy to built. For stereo channel, you need to build the two same circuits which will amplify the both of audio channels (right and left channel). Dual polarity / symmetrical power supply required for… Read More »

Stereo Tone Control with Line In + Microphone Mixer

This is an active stereo tone control circuit using very well known op-amp IC of TL072. The circuit include mic pre-amp and mixer control. In this design, we have two inputs: one for line (stereo), one for microphone and has control of the three audio frequency (high/treble, medium and low/bass). It also provide balance control… Read More »

5 Band Graphic Equaliser Project

Equaliser circuits typically divide the audio spectrum into separate frequency bands and have independent gain control for each band. The output of each band is mixed at IC4(A) and then fed to an audio power amplifier. Proper quality factor (Q) needs to be selected to avoid overlap in adjacent bands as this introduce colouration into… Read More »

Low Cost Mosquito Repellent

Here is the simple and low cost mosquito repellent circuit design. The circuit serves to keep the mosquitoes out of the room or the location where the device is installed. According to certain publications, the frequency emitted by the male mosquitoes is said to be around 20—25 kHz, and so within the realm of ultrasound.… Read More »