power supply for computers - composite and compact

composite and compact It seems that we cannot publish too many mains power supply projects: the number of readers" requests for these exceeds that for any other topic. To satisfy many readers, here is a computer power supply which can be built in a small space, pro- vided you use the toroidal trans- former shown. You may, of course, use three single transformers where space allows. In the positive supplies we have used type TEB or LM 0338 voltage regulators, the output of which may be fixed by two external resistors: R1/R3, R2/R4, and R8/R7 respect- ively. Resistors R1 and R2 may be replaced by a 270 ohm resistor in series with a 220 ohm preset so that fine control of the output voltage is available. The maximum output cur- rent of these regulators is 5 A: at this value internal current limiting comes into action. However, when both 5 V lines are used simul- taneously, the maximum combined current must not exceed 6 A. This restriction does, of course, not apply when individual tra...