"Cydrome Leader"
Phil Allison
"Gareth Magennis"


I recently bought some TIP35C transistors from Farnell UK. Just before
I
fitted one to an amplifier I thought I'd just check the pinouts.
Good job I did because instead of BCE they measured BEC.


** That is just not possible.

The middle leg is always the collector and metal tab used for
heatsinking.

FFS - get an ohmmeter and verify that simple fact.

Seems your dopey microprocessor ( ie software) based POS has gone ape and
confused Collector with Emitter.

Agreed.

those component testers are sketchy in that you have no idea what they are
doing or how they draw conclusions.


** Exactly.

The tester that Gareth has operates at very low currents and voltages - a
couple of mA at most.

Some power BJTs lose all current gain at that level, showing Hfes of maybe 1
or 2.

Very likely, this is fooling his meter into giving wrong info about C and E
terminals - since the reading is like that when C and E are reversed.

The tester I designed operates from a 12V supply and one sets the base drive
current with a wirewound pot to get 0.5 amps from the supply.

A calibrated scale gave the base current as a ratio to that current - or
Hfe.

Small signal "Beta" testers are USELESS for this job.


..... Phil