1.5W Audio Amplifier with IC SSM2211

This is 1.5W audio amplifier circuit design based on wide bandwidth, low distortion power IC SSM2211 from Analog Devices. This circuit is simple, inexpensive and easy to built with only contains few components. The SSM22111 is a high performance audio amplifier that delivers 1 W RMS of low distortion audio power into a bridge-connected 8… Read More »

CD/DVD/Bluray-Disk Drives Troubleshooting and Repair Tutorial

This is the CD Drives troubleshooting and repair tutorial for your electronic service reference. It should be work and also largely relevant for DVD/HD DVD/Blu-ray equipment. This document was developed specifically for the troubleshooting and repair of the CD players in component stereo systems, compact stereos, boomboxes, car units and portables, as well as CDROM… Read More »

Active FM Booster

This is a simple low cost circuit of an active FM booster that can be used to amplify the FM band signal, so you can listen the FM channels/programs from distant FM stations clearly. The circuit make use of a common-emitter tuned RF preamplifier wired around VHF/UHF transistor 2SC2570. (Only C2570 is annotated on the… Read More »

Digital Variable Resistor / Potensiometer DS1669

The DS1669 is an electronic digital rheostat manufactured by Dallas Semiconductor. This component has a function similar to digital variable resistor/potensiometer which can be operated by push the buttons. You can adjust the audio volume, LCD contrast, frequency, etc. by using two buttons instead of a common potentiometer/trimpot. This circuit explains how we do it… Read More »

6V / 9V / 12V Battery Charger with Constant-Current Charging

This is the circuit diagram of battery charger which has many important features such as current-constant charging, overcharge protection, short-circuit protection, deep discharge protection and more. The constant-current charging is a popular method for lead-acid and Ni-Cd batteries. In this circuit, the battery is charged with a constant current that is generally one-tenth (1/10) of… Read More »