12V 4A Solar Photovoltaic Battery Charger

This is the circuit diagram of 12 Volts, 4 Amperes Solar Photovoltaic (PV) battery charger which will be suit to charge a 12V battery or accumulator. The circuit handles up to 4 amps of current from a solar panel, which equates to about 75 watts of power. A charging algorithm called “pulse time modulation” is… Read More »

Ding-Dong Door Bell

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.

2KM Long Range FM Radio Transmitter

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 distance… Read More »

Electronic Appliance Protector

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.

Stage Center Reverb Guitar Effect

This is the simple spring reverb guitar effect circuit that can be built low cost and just requires a minimal amount of electronic parts and of course need minimum space for the circuit it self. The circuit also easy to built, it need 9V DC supply to work.

Infrared (IR) Cordless Headphone

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 without… Read More »

Uninterruptible Power Supply with PIC17C43 Microcontroller

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 interruptions… Read More »

2W RF Amplifier with MOSFET LF2810A

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 12… Read More »

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