Tag Archives: Boschert XL750-2636R

Sun 2/120 power supply

The standard power supply for the Sun 2/120 was the huge Boschert XL750-2636R power supply:

Sun 2/120 PSUIt can be hardwired for either 110V or 220V operation, through soldered jumpers in the above hole, which usually has a rubber cover, but in the photo I’ve removed it. Coming from the USA, mine was naturally set for 110V so I needed to change it to 220V, which meant desoldering the three lower jumpers and solder in a top jumper:

Sun 2/120 PSU 110/220VWith the three jumpers desoldered and one reused to set operation for 220V:Sun 2/120 PSU 220VSpecifications (maybe for those planning a modern replacement):

Sun 2/120 PSU specsThe seven connections that go to the Multibus backplane:

Sun 2/120 PSU backplane connectionsThe power supply has a large external EMI filter:

Sun 2/120 PSU EMI filter

The IEC connector goes to the EMI filter, and there should be a fuseholder in between the two black cables, but is missing here, and I’ll have to get a replacement:


Sun 2/120 PSU IEC connectorThe connections’ side of the power supply, obviously I should replace the “115 VOLT” label with a “230 VOLT” one:

Sun 2/120 PSU connections