This is LED emergency light that will turned on automatically when mains supply fails, and turned off when mains power resumes. This circuit produces highly bright because the use of ultra bright white LEDs. This circuit also has its own battery charger. When the battery is fully charged, the charging process will stop automatically.
This is the circuit diagram of Digital Tachometer / Digital RPM Meter which can be used for cars or motorcycles with 2 and 4 stroke petrol engines with any number of cylinders and contact breaker or electronic ignition systems. May be used as a general purpose revolution counter. Digital Tachometer Mainboard Scheme:
Above circuit diagram is a easy, simple and cheap switching voltage regulator which has capability to deliver adjustable voltage output range of 1.8V to 32V and static electric current of 3A. This regulator use adjustable regulator IC of LM317HV and a power PNP transistor of 2N3792.
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:
This is 1W stereo audio amplifier with LM386N. The output power is 1 watt for each channel, so it should be use two ICs of LM386N National Semiconductor for stereo channel. This circuit belongs to kitsrus.com and the kit is available there or at electronickits.com. This circuit only need 10mA current with best voltage supply… Read More »