Types of Power Supplies

2010-09-07 15:58:26 Author：Theone CopyFrom： Hits：0

If your equipment uses an AC adapter, see the sections on those devices.

The power supplies built in to consumer electronic equipment are usually one of three types or a hybrid combination of these:

1.  Power transformer with linear regulator using 78/79XX ICs or discrete components. The power transformer will be large and very near the AC line cord.

2.  Power transformer with hybrid regulator like STK5481 or any of its cousins - multioutput with some outputs switched by power on. If it has one of these, check ECG, SK, or NTE, and someone can probably provide the pinout. Again, the power transformer will be large and very near the AC line cord.

3.  Small switching power supply. Most common problems: shorted semiconductors, bad capacitors, open fusable resistors. In this case there is usually no large power transformer near the line input but a smaller transformer amidships. This is rare in audio equipment as the switching noise is difficult to keep out of the audio circuits. These are more often found found in some VCRs, TVs, monitors, fax machines, and printers.