Search found 5 matches

by mnphysicist
Tue Apr 23, 2013 10:39 pm
Forum: General Discussion
Topic: PID Thermo controller
Replies: 64
Views: 993413

Re: PID Thermo controller

I'm thinking of ordering one of these little jobs off ebay for a couple garage apps. It looks like a cool device, especially at those incredible prices! It seems a lot of folks are using SSR's with these and I didnt see any mention of fire prevention. It may be that most folks are using heating elem...
by mnphysicist
Wed Mar 02, 2011 7:57 pm
Forum: General Discussion
Topic: Clean wiring and connectors
Replies: 3
Views: 17820

Re: Clean wiring and connectors

The following from IPC may seem like overkill, but it has saved many a ton of grief. Generic low priced tools may or may not do a good job, as such it is important that you test and verify your process. There is nothing worse than having to deal with crimps randomly failing underneath ones dash. htt...
by mnphysicist
Wed Mar 02, 2011 7:52 pm
Forum: General Discussion
Topic: best way to remove solder flux?
Replies: 10
Views: 49494

Re: best way to remove solder flux?

Be aware that solder mask issues, flux type, and process temps can change properties enough that one type of cleaning may work fine, and then on another run of boards it wont. In the old days, we'd plot a grid array with terminations on the carrier part of the pcb assembly just for periodically test...
by mnphysicist
Wed Mar 02, 2011 7:40 pm
Forum: General Discussion
Topic: PID Thermo controller
Replies: 64
Views: 993413

Re: PID Thermo controller

One other possibility since the unit is likely built at lowest possible cost. If the pcb's are not properly cleaned... and IPC specs can be useless when it comes to low level signals, it is quite possible leakage currents across the PCB are raising havoc. Usually in final production test, thermocoup...
by mnphysicist
Wed Mar 02, 2011 7:30 pm
Forum: General Discussion
Topic: PID Thermo controller
Replies: 64
Views: 993413

Re: PID Thermo controller

I'm not familiar with this make and model, but have designed tons of similar devices. Most units have a thermocouple break protection circuit, either a constant DC bias, or a pulse. The idea being if the thermocouple opens up, the controller will go into an overrange mode, and shut down its outputs....