From our collection of circuits projects, we bring to you a list of 11 popular ones to help you out! Enjoy!
1. Handy Tester
For beginners, here is a low-cost multitester that can be used to test the condition of almost all the electronic components from resistors to ICs. It uses only a few components but can also detect polarity, continuity, logic states and activity of multivibrators.
Here’s a PC-based lighting system that lets you light up a candle using matchsticks by just pressing the ‘Enter’ key on the PC’s keyboard. It is especially useful when celebrating such occasions as birthdays and anniversaries.
This simple circuit monitors the mains distribution box constantly and sounds an alarm when it senses a high temperature due to overheating, helping to prevent disasters caused by any sparking in the mains box due to short circuits. It also automatically switches on a bright white LED when the power fails. The LED gives ample light to check the mains box wiring or fuses in darkness. The circuit beeps once when power fails and again when power resumes.
Using this light-operated circuit, you can close or open the door of your room remotely from your bed. You just have to focus the torchlight on the light-dependent resistor of the circuit, which you can install inside your room at a suitable position.
Here is a simple clap-operated electronic switch. Using this switch, you can turn on any appliance by clapping five times and turn it off by a single clap. The switch activates the appliance only if you apply the right clap code (five claps here) within the preset time (10 seconds). If you apply a wrong clap code (other than five claps) or you are unable to apply five claps within 10 seconds, the switch does not activate the appliance.
This optical burglar alarm uses two 555 timer ICs. Both the ICs are wired as astable multivibrators. The first astable multivibrator built around IC1 produces low frequencies, while the second astable multivibrator built around IC2 produces audio frequencies.
The most frequently used device in electronic workshops and laboratories is a universal power supply that provides a variable, fluctuation-free output. Here we present a variable power supply with digital control that is simple and easy to construct.
8. LED Torch
LEDs are becoming increasingly popular in many lighting applications. White LEDs are now common in torches. Here is a simple and economical LED torch that operates off two 1.5V cells.
This circuit lets you turn on/off a fan by just directing torchlight or other light toward its light-dependent resistor (LDR). The circuit is powered from a 5V power supply.
10. Window Charger
Keep away intruders with this compact electrified window charger. The charger produces non-lethal shocks that are strong enough to threaten intruders.
11. Visitors Counter
Presented here is a simple counter that counts the number of visitors entering or exiting an auditorium or any other place where you have installed this circuit at the gates. On receiving an interrupt from light-dependent resistor (LDR) sensors, the circuit increments the count and shows it on a 7-segment display.
Author is a senior correspondent with EFY.