Electronic Circuits and Diagram-Electronics Projects and Design

12V/120mA switch mode power supply circuit. Transformer less switch mode power supplies have become very popular these days. The circuit shown below is of a 12V/120mA output, 85 to 230V AC input transformerless switch mode power supply using LNK304 IC. Applications of a power supply based on this IC includes hand held devices, timers, small appliances, LED drivers, industrial gadgets etc. LNK304 is a low component count, efficient off-line switcher IC that can support buck, buck-boost and flyback topologies. The IC has a built in auto start circuit for short circuit and open loop fault protection. Other features of LNK304…

Switching regulator . Switching regulators work by drawing small amounts of energy from the input source and transferring it step by step to the output. This task is attained by using an electronic switch (operating at a predetermined frequency) which works like a gate between the input energy source and the output. This gate controls the amount of charge that is transferred to the output load. The output voltage of the switching regulator depends on how much time the switch is maintained closed. If the OFF time of switch is long then less energy will be transferred to the output…