tag:blogger.com,1999:blog-8869371566442567811.post987424624349019270..comments2024-03-27T23:23:05.548-07:00Comments on Rescue 1130: 2014 Pickup of an IBM 1130 System and More: Wiring SAC socket into new enclosure, plus zeroing in on the keypunch interface reset issueCarl Claunchhttp://www.blogger.com/profile/00359841432891565909noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8869371566442567811.post-79178300346134655432014-11-14T22:24:10.419-08:002014-11-14T22:24:10.419-08:00A possibility - although I am pretty well isolated...A possibility - although I am pretty well isolated from the circuits. The Arduino is connected to relay boards in my box - these relay boards have photoisolators to decouple the Arduino from the small relay on the board. That relay switches contacts which activate the solenoids/relays down in the keypunch and I have arc suppression in place for those contacts. Still, no way that the voltages can flow through wiring. <br />My reed switch to detect whether a card is registered (actually detects if the card lever relay is energized, which means the same thing), is only coupled magnetically. <br />The sensing pins are isolated by the DUP replays from the rest of the keypunch while I use them. <br />There may be EM coupling but it isn't flowing through connected wires, it is induced, if that is the cause. <br />Maybe my choice of a shiny plastic enclosure wasn't so smart, if a metal enclosure would have blocked any fields. <br />Still don't really know what is causing the problem, but I will figure that out in order to make whatever correction is necessary.Carl Claunchhttps://www.blogger.com/profile/00359841432891565909noreply@blogger.comtag:blogger.com,1999:blog-8869371566442567811.post-13475838104012965792014-11-14T08:29:44.227-08:002014-11-14T08:29:44.227-08:00Re the Arduino resets: could it be transients? The...Re the Arduino resets: could it be transients? The inside of a KP is an electrically noisy place, with big armatures picking and dropping, relay contacts making and breaking fairly juicy current loads, plus the transient mechanical loads on the motor would make its current draw jump up and down. Maybe some random spikes of voltage are coming back up your cable to reset the Arduino? I seem to recall there are bypass capacitors around quite a few relay contacts to suppress arcing. Maybe one or more of those has opened up with age? Or it could be normal noise that is unimportant to a relay system but hard on microelectronics?David Cortesihttps://www.blogger.com/profile/06760661115101469280noreply@blogger.com