TIP42 help...

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eyevancsu

New Member

• May 25, 2003

• #1

im not sure i wired the transistor right but....i applied 9v to the emitter ( as the schematic says, i think) and measured 9v coming out of the base but only around .1v coming out of the collector, does this seem right or should there be a much higher voltage coming out of the collector? or did i wire it wrong...

regards,

ivan

 

Sebi

Active Member

• May 25, 2003

• #2

I've posted a small picture to projects forum.

 

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eyevancsu

New Member

• May 25, 2003

• #3

since i only have the one tip42 already soldered i guess ill de-solder it to test it in your pic, thx for the help. But just to make sure, approximately how much should the voltage be comming out of the collector, maybe a guess ( the emmiter and base have around 8-9v).

 

Roff

Well-Known Member

• May 25, 2003

• #4

If you only have one TIP42, you may soon have one dead TIP42 if you use Sebi's test circuit.
With no resistor to limit the collector current, this transistor could draw as much as 2.8 amps, dissipating 25 watts until it burns up unless you have a big heat sink on it.

 

Sebi

Active Member

• May 25, 2003

• #5

Hey Ron,

in my test circuit is a small 12V 500mA bulb in collector... Maybe the symbol not international.

 

Roff

Well-Known Member

• May 26, 2003

• #6

Sorry Sebi, I thought maybe it was a current meter. It would have been helpful to label it as you did the other components.