On Fri, Dec 8, 2017 at 2:04 AM, Jeffrey Jonas via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I met a fellow who used an analog computer for factory molding (making parts with a heated mold). The heater control was not just a thermostat but calculated the acceleration of heat transfer to keep the part at the proper temperature. Definitely the job for an analog computer (till recently).
I'm unsure what tech was used (tubes or transistors).
Depending on the size of the heating elements that where switched, probably tubes, Bridgeport lathes used Thyratron tubes for speed control into the late 70's, when they started to replace them with SCR's. Big power was not easily switchable with transistors until the mid 70's. It was a big deal that RCA could make a color TV horizontal/HV section out of SCR's in 1969 in the CTC-40 sets. -- Matt Patoray Owner, MSP Productions KD8AMG