Ferroresonant transformers and 3278

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 > >