Murphy's Laws for Electronics: If wires can be connected in two different ways, the first way blows the fuse. If anything is used to it's full potential, it will break. If you understand it, it's obsolete. The most expensive component is the one that breaks. The reliability of machinery is inversely proportional to the number and significance of any persons watching it. A dropped tool will land where it can do the most damage. Each individual circuit will work perfectly but after combining them to create a system there starts the "Marriage Effect" Any wire cut to length will be too short. Milliammeters will be connected across the power source, voltmeters in series with it. The probability of an error in the schematic is directly proportional to the trouble it can cause. The bleeder resistor will quit discharging the filter capacitors as the operator reaches into the power supply enclosure. Mike Loewen mloewen@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/