29 Jun
2004
29 Jun
'04
10:04 a.m.
Hello list,
I have the possibility of acquiring a RX02-BA 115VAC/60Hz standard North
American power. I have a couple of questions concerning the feasibility
of a power conversion on it.
It is _very_ non-trivial
After studying the schematics of H771 of the RX01/02 units and the
manual, there are 4 things to do for a power conversion:
1. Replace H771-A with H771-C or H771-D.
2. Replace power harness
3. Replace belt and pulley
4. Replace circuit breaker
Here my questions:
1. From the schematics, the difference in H771-A and H771-C or -D is the
transformer has no center tap on the US supply. Does this mean that
there's no way for a DIY conversion job? Or it just mean that the
transformer does have a center tap and it's just unwired?
There's rahter more to it than that. IIRC the transformer in the is PSU
is a ferroresonant type, and provides part of the voltage stabilisation.
There's an extra winding on the transformer connected to a capacitor, and
that resonates at some harmonic of the mains frequency. You can't even
run this PSU off a step down trnasformer if the mains frequency is different.
What this means is that the transformer is different between 50Hz and
60Hz models. Unlike some other PSUs, I don't think there are extra taps
on the auxilliary winding which are used to switch between mains frequencies.
The good news is that the PSU is the same on RX01s and RX02s so you might
be able to find a 50Hz one.
2. Power harness is no big deal, I can just make a new one.
3. Belt and pulley; this is the tough one. Calling UK list members:
anybody has spares?
Err, bit of metal rod (stainless steel?) and a lathe? Presumably the
motor will now run at 5/6ths the speed it would have run at in the States
and therefore you need a pulley 6/5ths the size of the one that's there.
4. Can the circuit breaker still be bought in electrical/electronics
supply stores?
If you get a 50Hz spec PSU, it will have the right breaker built in.
-tony