> Wow, it's been a long time but I am pretty sure the early thyristors, > once triggered, couldn't be turned off, similar to the effect one got > with a pair of transistors triggering each other. (NPN-PNP > combination I think) > > DAW > Whatever a thyristors might have really been I wish I knew but I new the effects. Its made for a flash which recycled must faster than the flashes which came before. I assumed and I can see how I may be wrong that it was tied in to the Auto feature which had 4 settings each setting a color. If you were shooting something 5 or 7 feet away which was most often the case each flash did not use the entire charge of the battery so you could shoot several frames in 10 or 15 seconds. If you word the 510 battery on your belt like I did you could do this for many minutes till the thing got hot. I shot many Sports illustrated bathing suit issues with mine on tropical islands. With Elvis P. the art director and Marilyn M. the head stylist. The 285 could not use the battery pack so they came out with the 285HV which could. I got that one. In my last years in the 90's I used a Norman 200c with my Hasselblad or Rollei. Said good by to auto colors. Said hello to the inverse square law: Double or half the distance = Two f stops. Mark William Rabiner --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list