The following schematic shows a typical wiring diagram of the 200W DTK ATX PC Power Supply. This power supply circuit uses chip TL494 which is primarily designed for power-supply control and offers the flexibility to tailor the power-supply control circuitry to a specific application. This power supply has ATX design and 200W performance.
The TL494 contains two error amplifiers, an on-chip adjustable oscillator, a dead-time control (DTC) comparator, a pulse-steering control flip-flop, a 5-V, 5%-precision regulator, and output-control circuits.
Get more information about the 200W DTK ATX PC Power Supply Wiring Diagram using TL494 here (source: circuitsarchive.org)