Cold Circuits

[Ian]

I've been battling with a small accelerometer circuit for a rocket this last couple of weeks... it hasn't worked but I need it to finish my final university dissertation for 5 weeks time.

It doesn't seem to send data to the PC, but it can receive it. Not very useful as I can't get rocket data from it.

Anyway, after talking to the really helpful guy who works for them, he suggested putting it in the freezer... Guess what, it worked (for 30 seconds) after taking it out.

Anyone know why this is, and why cold temps would stop corruption? Got me puzzled!

 

[TriplexDread]

Maybe the heat from the circuit was causing expansion ending up with corrupt data?

 

[muckshifter]

In some cases you can do the same with a "faulty" hard drive ... long enough to get some data off.

I suspect you have a "problem" with the accelerometer circuit ... re-build it.

 

[floppybootstomp]

Yes, if some components overheat, the circuit will stop functioning completely or just in some ways.

You could buy yourself a tin of freezer from RS or other electronics suppliers, and probably identify the faulty component.

Start sending data. Spray each component with the freezer until you find the one (or maybe two) that enables data to be sent. Then either replace or heatsink that component.

I use that freezer spray to fault find at work, with audio amplifiers nine times out of ten it's the output transistors or chip.

Freezer Spray

 

[Ian]

Cheers Tony

I've got a bit further with the problem and it looks like it has something to do with the RS232 timing - I'm waiting for a surface mount connector to arrive from Farnell and then I'm going to re-flash it with lower timing speeds.

I can't wait for this project to finish, I seem to be eating, sleeping and breathing work at the moment!

 

[floppybootstomp]

Good luck

My link above didn't work for some reason but if you just go to the RS site and do a search for freezer spray you'll find it.