This add-on circuit automatically turns on your porchlight when your doorbell rings, so you can see the person ringing the doorbell at the doorstep....

Here’s a low-cost two-way intercom circuit with musical ringtone that can be made using readily available components (see Fig. 1). Melody generator IC UM66 (IC1)...

This ultra-bright white LED lamp works on 230V AC with minimal power consumption. It can be used to illuminate VU meters, SWR meters, etc....

Very often we forget to switch off the peripherals like monitor, scanner, and printer while switching off our PC. The problem is that there...

This solid state DC switch can be assembled using just three transistors and some passive components. It can be used to switch on one...

From understanding basic circuits to creating complex circuits, from analog to digital circuits, from designing circuits on PCs to circuits analysis, these free ebooks...

For fault diagnosis of any logic circuit, you need a probe that can test the logic level or existence of clock activity. The circuit...

You can play this game alone or with your friends. The circuit comprises a timer IC, two decade counters and a display driver along...

Very often when enjoying music or watching TV at high audio level, we may not be able to hear a telephone ring and thus...

The circuit presented here can be used in PCOs for displaying the actual bill. The comparative disadvantages of the presented circuit are as follows: 1....