Transistor Early Effect, Temp vs Hfe & Ft vs Hfe.... Messin' with the Curve Tracer

[andymouse]

You could teach me this stuff all day long, shame I didn't think like that years ago !! great video as always...cheers.

[mackfisher]

Tony I appreciate you filming these clips on basic theory, I love playing around on the bench with scrap components. I would get bored with watching you solder components in if it weren't for your tech talks thank you for taking the time to share. Stay warm

[poormanselectronicsbench]

I always say, it's good to have as much information as possible about things before you go into working on them, but, It's what you choose to do with that information that is important.
It's good to share any knowledge we can, and some creators will want to talk about specific things that may not concern others, so, the others might just want to look at other content.
Thank you for your work in sharing this with us!

[marcodoria]

Tony, thank you again for the time you take on bringing such subjects to us. Nevermind the negative comments. It's not like you are saying that this 1000$ iec mains cable is making your stereo sound better. You actually know what you are stating! Thanks again!

[stevent]

Tony- you can turn off the "forward " slash on your Scope, I have the Exact same setup (tek 2467B and 2465B) since you are already in X-Y mode while you have everything on as you do just simply turn off ch1 and leave ch2 on and you will find the slash is gone, ch1 is still enabled in x-y mode and with ch1 off you can still adjust gain, this is for the Tek 2400 Series Scopes, not sure how this setting affects other brands and model, your Videos are always Great !

[keybutnolock]

I love these 'quick n dirty' lessons. Even if it's over my head.
Thanks

[SeanBZA]

I remember some very early transistors with transition frequencies in the audio band, even down as low as 10kHz, which made them really great in power supplies, as they pretty much would be stable, but replacing them with newer parts would result in oscillation. Same for old 2N3055 transistors, some of the original designs relied on the transition frequency for stability, and putting in newer process transistors, marked 2N3055, but with modern processing that shifted the transition frequency up to 10's of mehgahertz, like the 2N3773, would result in the circuit oscillating and burning out the transistors. You had to add in extra filtering, like 10R and 470p into the base emitter side, to provide this extra filtering, and lower the transition frequency back down to make them stable again.

[derkmolenkamp]

Great video as always. A joy to watch!

[garygranato]

hi tony, thank you for this interesting video, and for taking the time to clearly explain. i could have watched another hour. cheers

[Tec]

Your videos bring me joy every day, Tony. Learning lots.

[radio-ged]

I completely forgot that I learnt that at college! Thanks for the refresh, very informative. I guess I forgot it because primarily I repair valve radios as a hobby and P.Cs/Laptops/Comms equipment as a job, so I don't deal with discrete transistors that much any more. Interestingly I've just watched a video by @Ptronix who touched on the subject of the Miller effect while building an active probe for a signal tracer. It's amazing how many things affect the performance characteristics of transistors and F.E.Ts. and divert them from their original performance specs.

[rolfts]

Thank you for sharing. (Good videos, as always) ..Have nice weekend.

[srtamplification]

I've been meaning to do a video on my little Hameg curve tracer module. This just gave me some inspiration.

[dhpbear]

'Audio-fool', really? You are no audio-fool, Tony! There are PLENTY of other videos that display audio foolishness on here!

[augustolacerda]

Loved the ring tone from the cellphone hahaha looks like it came out of a disney movie. but anyway, this basic theory videos are awesome. I'm currently reading AoE, i've been through the transistor chapter but I need to be honest that not all of it is very clear to me, sometimes I have to come back and re-read stuff. Maybe I should make some experiments along the way to visualize things better, I don't know. But anyways, These kinds of videos are awesome. Thank you for that. And greetings from Brazil! :)

[superrascal]

@4:20 Your popup maths should be 7 / 0.024 = 291.666 - ( You Put 0.024 / 7 = 291.6 ) I just thought I would let you know.

[jamesaguirre]

Tony this was perfect timing, I just finished building the kit and have started using it. As a novice calculating Hfe has been a challenge, and this really helps. This is probably obvious to many, but I have watched the video several times and reviewed the documentation I got with my kit (yours seems to have more detail) but I do not understand how you came up with the 1mv=1ma. I am asking because I also have a tracer built into the Digilent Discovery 2 and want to use it for small transistors. I was concerned that the 1mv=1ma may be tracer dependent.

[pisotones]

Excellent video but check that curve tracer as there must something wrong with it.
I've got the very same kit and mine does not display that diagonal artifact seen in yours!

[reinerfranke]

Thank you for the exellent explaination that most of the amplifier "tricks" is to workaround the physical effects. As an analog IC designer for 30y i would be very unhappy with the current state of model informations for discrete devices. That dissappoint people try to use Spice for discrete designs because the simulations results fail to match measurement on the boards. They blame the simulator but its the don't care policies of the vendors. Even complex analog ICs lack accurate interface and internal working models which could be simulated. The big A and T think its some kind of secrete but miss the essentials of a working engineering community.

Barry Gilbert gave a class in foundation desgin where he show how iterative incooperation of the more physical effects modelling allow a designer to separate the results and judge his circuit topology countermeasures. Prob. ADI think its to secret to heritage his knowledge.

For the "early" ist important to know that the "interpolated" crossing voltage depend on current and voltages as well. Its non-linear. And because of selfheating in static it could get infinite. I fight in early days that foundries should extract to better models like VBIC, Mextram, HiCUM and even today still HiCUM II is lacking specific effects in very high speed designs which are essential to analog design. To me ist a broken business model to think a lazy model support its part of a fab.

[dhpbear]

2:30 - At first I saw that artifact as the 'load line' :)