Basic split PSU with voltage regulation
Here's a small split-rail power supply suitable for messing about with ICs
and small circuits.
This 3D sketch shows the general layout...
The mains cable, fuse and power switch are on the back panel. I may add an indicator
lamp to the front panel, between the control knobs. Not sure whether to go for a mains
lamp, or an LED driven from the secondary - the transformer (from Maplin) has a rated
output of 15-0-15V at 250mA, so I'd like to use a low current LED to make sure there is
sufficient current for whatever the PSU is powering.
The Enclosure
The enclosure is a simple two-part aluminium case from Maplin (type AB24), 110mm wide,
68mm high, 133mm deep. This shot shows it with a UK pound coin on top for scale...
Here, the front and rear panels have been marked out and pilot holes have been drilled...
Front panel
Rear panel
I don't have screen printing facilities, so the panel lettering is done using a laminated
printout fixed to the case. Here's a shot showing a mockup of the front panel with the
fittings held on with Blu-tac.
The Circuit
Here's a schematic of the circut...
The circuit was built onto stripboard - the components are light and the board is held in place
by the two voltage adjustment pots. The front panel laminate was glued to the case using Araldite,
and the top cover was painted with green Hammerite. Here's a shot of the finished item...
|