Temperature controlled relay circuit
This temperature controlled relay circuit is a simple yet highly accurate thermal control circuit which can be used in applications where automatic temperature control is needed. The circuit switches a miniature relay ON or OFF according to the temperature detected by the single chip temperature sensor LM35DZ. More >
Simple water detector circuit
This simple water detector circuit uses alternative voltage in order to prevent the corrosion of the electrodes. It is easy to build and uses N1 as a trigger Schmitt gate which generate the AC. If between the electrodes is a electricity conductor, for example an aqueous solution, then because of the rectification action of D1 and D2, the C4 capacitor is charging. More >
Flashing Lights Circuit
This flashing lights circuit can be used as beacon. The assembly consists basically of two blinking steps that commands two light bulbs. With the help of P1 you can adjust the flashing frequency between some limits. More >
Telephone ringtone generator circuit
This is a simple home telephone ringtone generator circuit which is built with applying only several electronic components / parts. It generates simulated telephone ringtone and requires only DC supply with 4.5V DC to 12V DC voltage.
One may possibly use this circuit in ordinary intercom or phone-type intercom. The sound is pretty loud when this circuit is operated on +12V DC power supply. Even so, the volume of ring sound can be adjusted. More >
Program Remote Control IR Transmitter
Program Remote Control IR Transmitter
This project is based on integrated circuit from Holtek Semiconductor HT6221/HT6222. Similar parts used to be produced by NEC Semiconductor uPD6121/uPD6122. These ICs are commonly used in television and VCR infra red remote controls, garage door controllers, car door controllers, security systems and other remote control applications. More >
Led-based running display
Here is a circuit that creates an eye-catching running display effect using LEDs. It can be used to light up borders of animations, pictures, etc, and also for short word displays. More >
Vibration Sensor/Detector circuit
With the help of a simple ceramic piezo-electric detector it is possible to assemble an interesting and useful Impact sensor unit,which can be used to detect impact and vibration on doors, showcases, windows etc. More >
Solar Charger
Here is a solar charger circuit that is used to charge Lead Acid or Ni-Cd batteries using the solar energy power. The circuit harvests solar energy to charge a 6 volt 4.5 Ah rechargeable battery for various applications. More >
Digital thermometer circuit
A simple digital thermometer circuit with out a micro controller and having a seven segment LED read out is shown here. More >
Laser-guided Door Opener
This automatic door opener can be made using readily available components. The electromagnetic relay at the output of this gadget can be used to control the DC/AC door-opener motor/solenoid of an electromechanical door opener assembly, with slight intervention in its electrical wiring. More >