Digital Stop Watch
Here’s a digital stop watch built around timer IC LM555 and 4-digit counter IC with multiplexed 7-segment output drivers (MM74C926).
IC MM74C926 consists of a...
Under-/Over-Voltage Beep For Manual Stabiliser
Manual stabilisers are still popular because of their simple construction, low cost, and high reliability due to the absence of any relays while covering...
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...
