testing transistor temp sensitivity

[lowell]

how does one go about heating up and cooling down xistors? I've been reading some post that suggest that when troubleshooting, for example, oscillations.

[black_labb]

ive tested for runaway heat with my fingers when troubleshooting an amp (instead of blowing 10$ worth of transistors i turned it off when it heated up too much). not sure if thats what your looking for though

[Steve Conner]

Freezer spray and a hairdryer.

[Enzo]

Exactly my first thought too.

To heat small areas and individual parts a hairdryer works. You can buy a real heat gun, but they are not cheap. They get a LOT hotter than a hair dryer, and I also use mine to shrink heat-shrink tubing. COmes with little attachments to direct the hot air to small places.

SOmetimes you just want to warm the whole thing up some. FOld a bath towell and lay it on top of the circuit. That will let heat build up. Or a reflector bulb in a clamp-on light socket sitting right over the circuit. The 120 watt one over my bench to light up close work also throws off some heat, especially if you are only a few inches from it. You could even get one of those "heat lamps" from the store for th socket. Those things are for heating the whole thing up.


circuit chiller - used to be plain Freon in a spray can - will direct a stream of instant freeze on a small area and chill parts instantly. In a pinch, a squirt of contact cleaner will also chill a part, if you have no Freezit. Not as much as the stuff made for the job, but often it's enough to tell if the part is sensitive. SPray cans of Redi-Whip will also cool circuits, but I don't recommend it.

And really, a little TO92 xstr or even a small resistor, to cool it a litle, just pinch it between the jaws of your small pliers. The metal will conduct some heat away. DOn't crush the thing, just grip.

[Gtr_tech]

You can also take a can of duster air and turn it upside down....instant freeze spray.

> SPray cans of Redi-Whip will also cool circuits, but I don't recommend it.

WHIPPITS??!! Naw....it makes the transistors giggly and slow

[lowell]

thanks guys!