Discrete Semiconductors
1N4002 or 1N4004
D1, D2, D3, D4, D5, D6, D11
Because of space limitations D5 and D6 have to be fitted to the board after fitting the PSU1
and PSU2 headers.
1N5401
D7, D8, D9, D10
D9 and D10 do not need to be fitted if you are using a single phase wall wart or line lump.
However, for full wave rectification D9 and D10 are required. So if you are using a split
output line lump or an internal transformer with twin secondaries D9 and D10 have to be
fitted.
LED
This is an optional part and can either be fitted direct to the board for fault finding use or to
the front panel as a 'power on' indicator. For the latter I would suggest that you fit 2-way 0.1”
KK or MTA header on the board in place of the LED.
5mm green LED
AC
Integrated Circuits
LM317T 1A variable regulator
U1
LM337T 1A variable regulator
U2
Ensure that both devices are TO-220 types and not any surface mounting or TO-3 packages. I
much prefer the devices that are made by National Semiconductor. They are available from
other manufacturers but National's devices have a thicker and more rigid heatsink tab.
Do not fit solder these into the board just yet. They are only to be soldered once the board is
fitted to the panel. See the section on mounting the RPSU board later in this document.
4
