Ferroresonant transformers and 3278

Paul Berger phb.hfx at gmail.com
Thu Dec 31 06:33:55 CST 2015

On 2015-12-31 7:17 AM, Mike Ross wrote:
> On Jan 1, 2016 12:05 AM, "jwsmobile" <jws at jwsss.com> wrote:
>> On 12/30/2015 11:45 PM, Mike Ross wrote:
>>> Thanks for the thought... my main concern is the System/3s and Henk
>>> Stegeman - who has forgotten more than most of us will ever know about
>>> S/3! - says that 60Hz S/3 on 50Hz power is a no-go. Different voltage,
>>> fine - transformer can be restrapped. Different frequency... trouble!
>>> And then there are rotary machines of course. I bet you half my disks
>>> drives need the right frequency or a spindle pulley change.. and even
>>> then *they* probably have ferroresonants in their power...
>>> Mike
>> Order a boatload of 8kw honda generators?  I think you could get 40 amps
> out of them.  Any reason the power has to be in phase?
>> I know for the mainframe power that might not be high enough, but on
> smaller machines it would take care of the problem.
>> thanks
>> JIm
> Jim most of my 'interesting' machines - both S/3s, S/38, 1800, big disk
> drives - do need three phase 60Hz. The 2741s, 3741, 5496, S/32, S/34, &
> S/36 are single phase but almost certainly need 60Hz for power supplies
> and/or disk drives
> On the plus side all of the stuff I brought over from the UK will work fine
> - includes pdp-15s, pdp-12s, KL & KS 10, and a bunch of RK05s with 50Hz
> pulleys! They all take 240V 50Hz.
> Mike
All of those IBM machines you listed will have resonant capacitors in 
the power supplies, and all have at least one synchronous motor inside, 
not to mention all of the AC fans inside the machines.


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