1 – 9V Variable Desktop Power Supply

Here the variable desktop power supply which will convert a high input voltage (12V) from the SMPS / PSU of a desktop computer into small output voltage (1.25 to 9 volts). This converter will be very beneficial for electronics hobbyists. An adjustable three-pin voltage regulator chip LM317T (IC1) is applied right here to deliver the… Read More »

Power Supply Failure Alarm

This is the ‘special’ circuit design of power supply failure alarm. The vast majority of the power supply failure alarm / indicator circuits require a independent power supply for themselves. However the alarm circuit introduced right here requires no extra supply power source. It utilizes an electrolytic capacitor to hold sufficient charge, to supply power… Read More »

USB Powered, Stereo Computer Speaker

This is the circuit diagram of USB powered stereo computer speaker, or it widely known as multimedia speakers for PCs. The circuit has single-chipbased design, low-voltage electrical power supply, compatibility with USB power from computer, simple heat-sinking, inexpensive, large flexibility and wide temperature tolerance. At the heart of the circuit is IC TDA2822M. This IC… 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 »

Car Cigar Lighter to USB Power Socket

Here is the schematic design of car cigar lighter to USB power port. Nowadays, almost all computer systems have logic blocks for working with a USB port. In practice, a USB port is capable of supplying more than 100 mA of continuous electric current at 5V to the peripherals which are hooked up with the… Read More »

65W Power Amplifier using HEXFET

This is a high quality 65W power amplifier circuit based HEXFET IRF9540 and IRF540. The circuit is quite simple for amplifier with good sound quality. The component parts is easy to find at electronic store around your place. It uses split power supply. Q8, Q10, Q11, Q12, Q13 should be mounted on heatsink for thermic… Read More »