Here is the circuit diagram for LM 317 T voltage regulator with pass transistor .
A simple but less efficient method of controlling a DC voltage is to use a voltage divider and transistor emitter follower configuration. The figure below illustrates using a 1K pot to set the base voltage of a medium power NPN transistor. The collector of the NPN feeds the base of a larger PNP power transistor [...]
Three terminal regulators are just right when we need a single fixed voltage. But they will be cumbersome as a hobbyist works with different voltages at different times and it becomes unwieldy to keep power supplies with a number of three terminal regulators. Wouldn’t it be better if we have an adjustable but regulated power [...]
These are simple, effective and interesting integrated circuits. They are short circuit protected, can stand up to 32V, have thermal protection and they can easily deliver regulated voltage with 1 amp of current. In these ICs, the last two digits give you the regulated voltage they deliver, 7806 gives you 6 volts and 7812 gives [...]
Unfortunately our hobby circuits work on different voltages and a power supply with single voltage will not be sufficient. Simplest way would be to buy a multi-tapped transformer and connect the voltage taps with a suitable switch. These transformers are available with taps of 1.5,3,4.5,6,9,12V. We need a single multi throw switch (as many throws [...]
Make a full wave rectifier, as it is cheaper and better than a half wave one and has less AC ripple. Full wave rectification can be accomplished by two ways, either by a center-tapped transformer using two diodes, or by a bridge circuit, which uses four diodes. We need center tapped transformer as used in [...]
Half wave rectification is simplest, as it requires only one transformer, one diode and one capacitor, but we have added a LED to give power supply indication. A simple half wave rectifier for 12V is shown below 500mA transformers are generally used for these circuits. Connect the primary wires to the mains chord after carefully [...]