Welcome!

Build powerful and reliable self-contained alarm circuits with these innovative designs. Featuring three distinct alarm schematics – A, B, and C – each utilizes a Complementary Latch for minimal standby current, less than 2uA, dramatically extending battery life. Optimize performance and enhance siren output with adjustable R1 values.... [read more]

Transform a milliamp meter into a versatile volt meter and unlock precise current measurements with this essential guide. Discover how to calculate the perfect resistance for accurate readings, from 1K to 10K ohms, and master the art of scaling your meter for higher current applications.... [read more]

Build a powerhouse amplifier capable of delivering 60-90 Watts into 8 or 4 Ohms – a truly exceptional design for discerning audiophiles. This meticulously engineered circuit, featuring IRFP240 and IRFP9240 Hexfet transistors, unlocks incredible performance and delivers a rich, dynamic audio experience.... [read more]

Build a sophisticated and reliable burglar alarm system with this intuitive single-zone circuit. Featuring automatic Exit and Entry delays, plus a 15-minute Bell Cut-Off, this design empowers you to safeguard your property with precision. Easily integrates with normally-closed sensors like magnetic reed contacts and micro switches, and with a simple modification, accommodates normally-open triggers for comprehensive protection. Fine-tune delay times – Exit, Entry, and Bell Cut-Off – to perfectly match your needs, unlocking a powerful tool for proactive security.... [read more]

Build your own crystal radio receiver and unlock the secrets of 1070 KNX! This detailed schematic guides you through constructing a sensitive radio that pulls in strong LA stations with a 15 foot antenna, utilizing 200 turns of wire for optimal performance and a germanium 1N34A diode for superior reception.... [read more]

Build a portable cellphone charger and extend your travel adventures with this simple circuit, delivering power in just two to three hours. This innovative design utilizes a 12V battery and a carefully calibrated circuit to replenish your phone's battery, ensuring you stay connected on the go.... [read more]