This circuit is a wireless car alarm system that is built using two circuit modules, namely modules of transmitter and receiver modules. This circuit works on FM radio waves. Car alarms can be used on vehicles that have a 6-12VDC power supply. You can use the voltage stabilizer if your car power supply is too… Read More »
Here’s the 3V lamp brightness controller circuit diagram used to control the brightness of the light bulb. You simply use the two AA or AAA battery to make this circuit works. Example usage of this circuit is to adjust the brightness of images for close-up photo shoot with a digital camera. IC1 works to generate 150Hz… Read More »
This is a class AB 6-10W audio power amplifier circuit which built using a TDA2002 or TDA2003 power amplifier IC module. These are replacements for the original LM383 which is no longer available. It is easy to build and has a minimum of external components. The module has both short circuit protection and thermal protection.… Read More »
This is 25W low power inverter which contain of only 9 parts and turn 10VDC – 16VDC into 115V / 60Hz square wave power. This circuit has capability to operate AC equipment up to 25W. The first section of the 555 timer is wires as an astable oscillator with R2 and C1 setting the frequency.… Read More »
Here the circuit diagram of 25 watt Hi-Fi (high fidelity) audio amplifier that build based on single power amplifier IC LM1875 that should be run using heatsink attached on its. Components List: R1 _____________ 1K R2 _____________ 1M R3 _____________ 22K R4 _____________ 10K R5 _____________ 180K R6 _____________ 1R IC1 ____________ LM1875 C1 _____________… Read More »
This is a low noise and distortion pre-amplifier and tone control circuit in one module. Using a special IC TDA1524A, this simple circuit is easy to build and will drive most of power amplifier. Schematic diagram:
The following circuit is a simple fire alarm circuit based NE555 timer and use thermistor as a temperature detector. This sensor will activate the transistor when the temperature is in high value. The thermistor will have a low resistance at high temperature, while at low temperature, the transistor resistance is high. This characteristic of thermitor… Read More »
Here is the circuit diagram of ultrasonic sensor switch. There are many methods of wireless switching such as by using infrared, AM/FM signal, bluetooth, etc. This is an alternate wireless switching by using ultrasonic sensor. The distance of switching range should be more than 10 meters. This circuit produces and transmits ultrasonic sound of frequency… Read More »
This a simple stereo electret microphone pre amplifier circuit. The below design diagram is the design for single channel, but the design of PCB layout is for stereo design og electret mic pre amp. For maximum performance, better quality, use solid capacitors or film capacitors and metal film resistors (1% tolerance). schematic diagram: