In honor of the two fast motherboards that I burned, it took some time to study how the ATX switching power supply works

A search on Google found an ATX switching power supply consisting of TL494 and LM339

At first glance, more than 3842 of the switching power supply to be more complex in fact, as long as the basic circuit has a certain understanding and a certain imagination to understand this circuit is still very easy

First introduce the main chip of this circuit----TL494

This is his internal block diagram we can see 8 feet and 11 feet is the pulse output foot 13 feet is the power of the boot foot know the basic working principle of TL494 the principle of the whole machine is not complicated.

220V of alternating current in the full bridge BD1 rectification after the positive of the C5 to form about 300V DC power