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 »

Galaxy Audio Booster using RC4558

The following is an electronic circuit called galaxy audio booster which serves to improve the performance of your audio system. This circuit uses an IC RC4558 in which there are two op-amp modules that can be used for stereo audio applications. The circuit is similar to stereo tone booster that uses the principle of High… 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 »

Glow Plug Control Module

This is the glow plug control module unit to raise the air temperature inside the engine cylinder for quick and reliable starting, to extend the battery life and reduce the diesel consumption. In diesel engines, the air in the cylinders is not hot enough to ignite the fuel under cold conditions. Therefore every cylinder of… Read More »