ATX supplies using forward topology with single switch or double switch (half-controlled bridge). Transistors are MOSFETs. Control IC's are UC3842, 3843, 3844, 3845 or other IC's, which are a combo for boht supply and active PFC controll like ML4824, FAN480X and ML4800.

ICs TL494 and KA7500 are equivalent. The letters of 494 can differ. Theese supplies use bipolar junction transistors (BJT) of NPN type.

ATX PC SMPS's with DR B2003, marked as 2003. Theese supplies use bipolar junction transistors (BJT) of NPN type.

Supplies ATX with KA3511 integrated circuit. Theese supplies use bipolar junction transistors (BJT) of NPN type.

Schematics of ATX switching supplies with SG6105. Theese supplies use bipolar junction transistors (BJT) of NPN type.

KA7500B is litterally the korean copycat of Texas Instrument TL494.

ATX switching supplies with DR B2002 (marked 2002), AT2005 (2005) and its equivalents LPG899 and WT7520. Theese supplies use bipolar junction transistors (BJT) of NPN type.