This ding-dong door bell circuit might become the simplest and cost-effective door bell circuit. The circuit is designed based on single IC 8021-2 which manufactured Formox Semiconductors. It is an 8-pin DIP (Dual Inline Package) IC whose only four pins, as shown in the above circuit design, have been used.
This long-range FM radio transmitter has an additional RF power amplifier stage, after the oscillator stage. The extra RF power amplifier used to strenght up the power output to become 200-250 milliwatts. With a great matching multi-element Yagi antenna or 50-ohm ground—plane antenna, this transmitter can give great good signal strength up to a distanceâ€¦ Read More »
This is a easy built and very low-cost circuit purposed to protect your electronic appliances / devices, such as Personal Computer, TV, recording devices, refrigerator, and other devices during sudden tripping and resumption of home mains supply. Appliances like refrigerators and air-conditioners are more inclined to damage due to such conditions.
This is the schematic diagram of Infrared (IR) cordless headphone. Maybe it also can be called “wireless headphone”, but it use infrared as sound signal carrier. It use a pair of circuit diagrams that are IR transmitter and IR reveiver. Using this low-cost project one can reproduce audio from TV or other electronic devices withoutâ€¦ Read More »
This is a MicroChip Uninterruptible Power Supply (UPS) reference design with PIC17C43 microcontroller. The document is available to download from the end of this post. At times, power from a wall socket is neither clean nor uninterruptible. Many abnormalities such as blackouts, brownouts, spikes, surges, and noise can occur. Under the best conditions, power interruptionsâ€¦ Read More »
This is a 2W RF amplifier circuit build with single power MOSFET LF2810A. Figure A Figure A is the schematic of the microstrip single stage RF amplifier. The amplifier is based on the M/A-Com LF2810A MOSFET. The transistor is actually a 10 watt, 28 volt part, but provides adequate gain for this application at 12â€¦ Read More »
This easy to built circuit produces a warning beep when somebody crosses a secure area in your home or place of work. The transfer, hidden beneath the ground mat, causes the alarm whilst the individual walks over it. The circuit makes use of a behaviorive foam because the switch. it may be small items ofâ€¦ Read More »