Protection for Your Electrical Appliances
Here is a very low cost circuit for protecting electrical appliances, such as TV, tape recorder, refrigerator, and other instruments during sudden tripping and...
Toy Car: Infra-red Motor controller
This add-on circuit enables remote switching on/off of a battery operated toy car with the help of a TV/ video remote control handset operating...
Stereo Amplifier Using TDA7052 ICs For Portable Devices
Portable devices like personal computers, MP3 players, sound recorders, telephones and audible sensors are frequently in need of additional stereo amplifier to produce sufficient...
Smart Cellphone Guard
Smart cellphone guard presented here is in fact a simple infrared (IR) sensor alarm secures your cellphone with an invisible beam of light that...
Periodically On-Off Mosquito Repellent
Some of the mosquito repellent available in the market use a toxic liquid to generate poisonous vapours in order to repel mosquitoes out of...
Water-level Controller
In most houses, water is first stored in an underground tank (UGT) and from there it is pumped up to the overhead tank (OHT)...
3W/6W audio amplifier using TDA2003
This is a simple audio-frequency (AF) amplifier using the popular audio amplifier IC TDA2003. The IC comes in a 5-pin TO-220B package.
Audio amplifier circuit...
Sunset Lamp
LDR-based automatic lights flicker due to the change in light intensity at dawn and dusk. So compact fluorescent lamps (CFLs) are unsuitable in such...
Smart Emergency Light
An emergency light can come in handy at all sorts of time, especially when there's a power outage. Now you need not fear dark...
Numeric Water Level Indicator
Most water level indicators for water tanks are based on the number of LEDs that glow to indicate the corresponding level of water in...
Door Guard
This door guard uses operational amplifier µA741 and a light-dependent resistor (LDR). Operational amplifier µA741 is used as a sensitive voltage comparator. Preset VR1...
Electronic Bicycle Lock
The electronic bicycle lock described here is a worthwhile alternative for bicycle owners who want to make their bicycles 'intelligent' at reasonable cost. One...
Electronic Watch Dog
Here’s an electronic watch dog for your house that sounds to inform you that somebody is at the gate. The circuit comprises a transmitter...
Electrolysis-Free Water Level Alarm
In most water level monitors and alarms, corrosion of the probes makes the systems unusable in a few months. This water level alarm uses...
Laser Communication System
This laser communication system transmits sound or music signals through a laser beam. The intensity of the laser beam changes with the amplitude of...
Mini Candle Light Using Old Mobile Phone Battery
According to the three Rs—reuse, reduce and recycle—we must save our planet from e-waste. Sometimes we have a dead mobile phone whose battery is...
Get started with NOT Gate IC | 7400 Series Tutorials
NOT Gate Logic Symbol and Boolean ExpressionTruth Table for NOT gate ICRecommended Operating Conditions of NOT Gate IC 7404Pin-Out Diagram of 7404 NOT Gate IC7400...
TINY DEW SENSOR
Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. A low-cost circuit for a dew sensor described here can be used...