5W Power supply with TTL

The power supply in your pages is what I need, but how would you connect 5 terminals to the end, 3 to run operational amplifiers at +-12V (+12, 0, and -12V supplying 250mA, and 2 to run a digital logic element of 5V and 0V, (e.g. 1 and 0) needing 1A

Posted by Mark (mh51@sussex.ac.uk) on 15/01/2004, at 10:56 GMT

Multi Voltage PSU

I would probably use a dual 15v-0v,15v-0v transformer rated at about 20-25 watts or volt-amps. With the secondaries windings connected in series, as 15v-0v-15v centre tapped winding, run a W02 rectifier,with the 0v line connected to the transformer centre tap.Follow this with 2 2200u-4700u 35v smoothing caps, then (for the +v rail)connect a 78(S)12 followed by a 7805 voltage regulator connected in cascade,or to get a more stable +12v rail connect a 78S05 regulator direct to the +15v rail to withstand the greater voltage difference across itself (10v)or use 2 7812 regulators. For the -12v rail use a 7912 connected to the -15v rail. To further balance the load connect LEDs or 12v lamps to the -12v side. Further info can be found in Power Supply Projects by R.A. Penfold.

Posted by Anonymous on 14/08/2010, at 15:20 GMT