Solidstate Remote Control Switch
Here is a solidstate remote control switch which uses readily available electronic components. The control circuit comprises the transmitter and receiver sections. The range of...
Stabilised Power Supply with Short-Circuit Indication
Here is an efficient 4-stage stabilised power supply unit for testing electronic circuits. It provides well regulated and stabilised output, which is essential for...
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...
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...
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...
Low-Cost PCO Billing Meter
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....
40-Metre Direct Conversation Receiver
Using the circuit of direct-conversion receiver described here, one can listen to amateur radio QSO signals in CW as well as in SSB mode...
Ultra Low Drop Linear Regulator
The circuit is a MOSFET based linear voltage regulator with a voltage drop of as low as 60 mV at 1 ampere. Drop of...