I've been playing with electronics for 40 years, but there's still stuff to learn - even basic stuff about how transistors work. Here I measure the Collector/Emitter junction voltage when the transistor is turned on.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
Ha ha ha – I've been doing electronics work for 40 years also and never knew what the CE voltage drop was before today. I've been mostly in digital logic so I never really needed to know since everything in my world is either slammed to ground up pulled up to 5v and there's never any 'fine tuning' as it were, but it's good info because I do build and/or troubleshoot analog stuff every now and then. Thanks for the video 🙂
Back in the sixties I got a hold of a copy of the "GE Transistor Manual", these days it's available as a download online. There's a great deal of stuff in there that will remove that vagueness, and perhaps enlighten you on some things you weren't aware of. For example back then I didn't think that solid-state components would ever "wear out", but in fact if you're dissipating any significant power then thermal cycling will create an issue that will cause the device to fail over time. Lots of other good stuff in there, too…
I tried using a transistor in a pocket loudspeaker, but it combusted when i turned it on after briefly working. I decided to do some research into how to use the devices. I should probably not connect 12 volts to it with no resistor.
Just read the datasheet to get the operating parameters.
I recently went to purchase a (10k ohm 5% resistor) Ebay popped up that ppl who bought that resistor also purchased these.items .(2n3904 transistor) (.01uf50v disc capacitors) I dont want to buy some item thats used for terrorist crap,
The condition for saturation (I believe) is that the Vce voltage is less than the Vbe voltage. The effect is that the base is starting to get into forward saturation, this sort of limits how much base current you can have. I have some high voltage low current transistors with not all that much gain, and to get the many amps of current to flow through the load, I have to put nearly 5V directly across the base-emitter junction. That means the Vce voltage bottoms out around 4.3V or so. At this point if I try and further increase the Vbe, the Vce will increase in step with Vbe.
you should check out according to Pete from spark fun he does a good one on transistors
Dave and Derek mentioned in the same video. good stuff 😉
how much base resistor value should be if i am using using bc547 at 5v 75ma?
Vce sat is a spec usually found in datasheets.