On Sun, Jun 25, 2023 at 5:52 PM Rob Jarratt <[email protected]> wrote: > > Before I confuse matters too much I should point out that I was not using the > Rainbow power switch unit but one from a DECmate. I had erroneously thought > there was a fault with the Rainbow one. I think the fan supply may be > different on the DECmate switch, so ignore the bit about the fan turning.
It appears that there are 2 ways of powering (different types of) fans with this power supply. Whether one was used in the Rainbow and the other in the Decmate I know not. But anyway : A 12V DC fan running off the DC output of the power supply. This is the one shown in my schemtic for the supply. Note the jumper link in the fan power plug that means the supply doesn't get mains if you forget to plug the fan in. A 115V AC fan connected to the unused pair of pins on the AC input cable to the power supply (top right of the 'switch/fan assy' in my schematc. This uses the primary winding of the startup transformer as an autotransformer on 230V mains. Note that the latter fan will run if the chopper side of things is dead, the former won't. -tony
