Electronic Horn

This is an easy, low cost and easy built circuit of an electronic horn which is designed close to quadruple op-amp IC LM3900 (IC1). IC LM3900 has four independent operational-amplifiers (A1 through A4) having a large output voltage swing. It is able to operate at up to 32V DC. The 1st op-amp (A1) is designed… Read More »

4-Output Stage (5V/6V/9V/12V) Stabilized DC Power Supply

This is definitely an effective 4-output stage stabilized DC power supply unit for testing electronic circuits. It delivers very well regulated and stabilised output, that is important for most electronic circuits to provide good results. The circuit gives you an audio-visual indication if there is a short circuit in the PCB under test, so the… Read More »

Long Range/Distance Infrared Transmitter

Here the long range/distance Infrared transmitter circuit, give you extra power for your Infrared transmitter. The majority of the IR remotes do the job reliably within a range of 5 metres. The circuit complexity increases in case you design the IR transmitter for good operation more than a extended distance, for example, 10 metres. To… Read More »

1Hz Clock Generator with Chip On Board (COB)

This is the 1Hz clock generator circuit with Chip On Board (COB). Commonly, the circuits to produce 1Hz clock for digital clock and counter circuits applications implement ICs in conjunction with a crystal and trimmer capacitors, etc. Even so, equivalent or improved accuracy could be obtained working with a chip-on-board (COB) device found inside a… Read More »

ADC0808 – Simple Analoque to Digital Converter

ADC0808 – Simple Analoque to Digital Converter This is a very simple analoque to digital converter circuit based on 8-bit analog-to-digital converter ADC0808. Typically analogue-to-digital converter (A/D Converter / ADC) requires interfacing through a microprocessor to convert analogue information into digital format. This needs extra hardware and appropriate software, resulting in more complexity and hence… Read More »

Heat Detector + Siren

This is the diagram of heat detector circuit which already integrated with siren circuit in the output. This circuit applies a complementary pair comprising NPN metallic transistor T1 (BC109) and PNP germanium transistor T2 (AC188) to detect heat (because of outbreak of fire, for example) in the area and activate a siren/alarm. The collector of… Read More »