Watchman Watcher
Here is a circuit that can be used in offices, stores, warehouses, etc during night to check whether the watchman of your establishment is...
Low-Cost Electronic Quiz Table
Here is a simple, low-cost quiz table for four game participants. It determines the contestant who first presses the switch (S1 through S4) to...
Highway Alert Signal Lamp
Here is a signal lamp for safe highway driving. The lamp automatically emits brilliant tricolour light when a vehicle approaches the rear side of...
Doorbell-Controlled Porchlight
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....
Intercom with Musical Ringtone
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)...
Ultra-Bright LED Lamp
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....
Mains Manager
Very often we forget to switch off the peripherals like monitor, scanner, and printer while switching off our PC. The problem is that there...
Solidstate Switch For DC-Operated Gadgets
This solid state DC switch can be assembled using just three transistors and some passive components. It can be used to switch on one...
10 Free eBooks On Circuits
From understanding basic circuits to creating complex circuits, from analog to digital circuits, from designing circuits on PCs to circuits analysis, these free ebooks...
Versatile CMOS/ TTL Logic and Clock Probe
For fault diagnosis of any logic circuit, you need a probe that can test the logic level or existence of clock activity. The circuit...
