Ferroresonant transformers and 3278

William Donzelli wdonzelli at gmail.com
Wed Dec 30 23:29:14 CST 2015

Of course! Find the exception that proves the rule!


On Thu, Dec 31, 2015 at 12:23 AM, Guy Sotomayor <ggs at shiresoft.com> wrote:
> On 12/30/15 9:06 PM, William Donzelli wrote:
>> Sorry about digging up a slightly stale thread...
>>> I haven't done any troubleshooting yet but checking the manuals on
>>> Bitsavers tells me my US 3278s have ferroresonant transformers
>>> specified as 120V 60Hz only. This can be expected to cause problems
>>> with 120V 50Hz here in NZ from my knowledge of how ferroresonant
>>> transformers work; I'll get excessive magnetic currents - overheating
>>> - all kinds of nasties. I can wind the voltage down a bit and run them
>>> at 90-100V but that doesn't help much.
>> ...but straight from the horses mouth, most IBM ferroresonant
>> transformers will work at 50 or 60 Hz. The capacitor may need to be
>> swapped, depending on the equipment.
>> I was hanging around some IBM old timers this evening, including the
>> Big Horse at Endicott.
> I just looked up the FE manual for the 3278 and it shows 5 different part
> numbers for the
> ferroresonant transformer (depending upon region) and only a single part
> number for the
> capacitor.
> TTFN - Guy

More information about the cctalk mailing list