A custom power supply unit for the BugModular system.NOW SUPERCED BY PSU2 - ARCHIVE INFO ONLY
Any modular system requires a highly stable power supply unit (PSU) for decent operation. This unit generates the bipolar +/- 15v supply for the BugBrand system in a heavyweight external enclosure, conservatively rated at 500mA per side - enough for at least two full racks, possibly three depending on module choices. An external enclosure was chosen for expandability of systems and to keep the small amounts of heat generated away from the module circuitry. It also effectively encloses any mains wiring.
One end of the enclosure holds a standard IEC mains inlet (units are pre-configured for either 115v or 220-240v operation) with fuse-holder and power switch with built in light. At the other end are two 3pin power outputs to connect to the racks along with two LED power indicators and a common ground socket (black 4mm banana).
Based on the LM317/337 voltage regulators (with adequate heatsinking so things don't run too hot) along with large value, high-temperature filter capacitors and PCB mounted transformer (pre-configured 115v or 220-240v).
The PSU is housed in a custom 2 part enclosure - the lower part houses the circuit and input / output and uses 0.05" steel, while the upper shell is thicker 0.1" steel with side slots for ventilation. Rubber feet are affixed to the underside of the unit.
Note: Due to the solid steel enclosure, the PSU is weighty - this means that postage outside the UK is quite expensive.
Added on Saturday 03 January, 2009.