Ferroresonant transformers and 3278

[William Donzelli]

I bet you (or Mike, actually) could get it to work by trial and error,
swapping in caps. The transformers (generally) are apparently pretty
forgiving - being off in frequency just results in lost efficiency,
maybe 10-15 percent lost at most. Not flames, anyway.

--
Will

On Thu, Dec 31, 2015 at 12:30 AM, Guy Sotomayor <ggs at shiresoft.com> wrote:
>
>
> On 12/30/15 9:29 PM, William Donzelli wrote:
>>
>> Of course! Find the exception that proves the rule!
>
>
> ;-)  However, it would've been nice if it were only necessary to change
> the capacitor!
>
> TTFN - Guy
>
>>
>> --
>> Will
>>
>> 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
>
>