Why the base resistor in Darlington transistor circuits? With demo 

On topic content starts at 1:38 if you don't want to watch my intro. Ignore the resistors in the diagram when I discuss the gain calculation.

You explain like an experienced teacher. Well done! Today, I learnt something new from you. Thanks.

Great stuff. Definitely do more. RU-vid is full of BS EE videos. Nice to see someone really good on fundamentals.

Thank you, John. This helped me understand some missing links. I play bass guitar and I have been trying to find some new and inexpensive circuits to boost certain tones... as well as some inexpensive DIY preamp circuits that aren't too complicated. I really hope you and Snickers have a good start to the new year and thanks again.

I always wondered about the purpose of these base-emitter resistors embedded in an ULN2003, now I understand. Thanks a lot John !

John & Snickers - glad you got my Christmas card, it's great to see it arrived. Whoohoo. I wasn't sure what to send you, but I guessed you might have some fun with the MPSA14 darlington transistors. The other thing is a "Digispark compatible USB attiny85" (it's a bit random, but was the other next flattest thing I had to mail to you!) Snickers is doing great at 12 years old. I found the your vid on the base resistor very interesting - I hadn't realized before that it was to combat the effect of B-E capacitance - and you demonstrate well how that capacitance becomes more of an issue at higher frequencies too. It would be interesting to see how the Darlington transistor MPSA14 behaves too - as it doesn't have a base resistor internally so it should behave pretty badly at higher frequencies I'm guessing.

Hi John.. Very well explained and I would like to see more videos like this one. Happy Birthday Snickers. Has always I Liked,Shared and added to Playlists. And the Ad played this time. All my best. Bobby

Very nice and imformative explanation, and demonstration. I learned a lot watching this video. Thanks.

Wow just discovered your channel ! Great video 🙂👍👍

Thank you for interesting issue and explanation with test!

You are awesome brother thanks for your kind tutorials.

Great video! Learning alot from your videos, could you do a more in depth video on the darlington configuration

In depth video would get a like from me!

Nice explanation :)

It would be nice to see how to set quiescent current to ab class output stage that consists of two Darlington transistors (as a one piece).

Nice vid! I'm curious how that resistor affects the overall gain of the darlington pair.

Great video !! That incandescent lamp brought back memories of my childhood. Funny how the old socket board is all yellowed. I'm sure you don't really care about that. But have you ever seen a RU-vid channel called "The 8-Bit Guy"? He restores old computers and consumer electronics. He's done a lot of experimenting with yellowed plastics and he shows some techniques for getting them back to their original color... more or less. (Just a random comment, has nothing to do with the actual content of this video.)

Does darlington circuit boost up AC current gain or DC current gain?

Excellent. I'm curious as to the change in input current when the resistor is added - i.e. exactly how much gain was traded away to get the improvement in turn-off speed.

Love the ending!

Thank you!

Great videos! Love to watch them. Say hi to your kitty. I myself have a small doggy that is with me in my lab all the time, his name is psycho. He doesn't like cats though...sorry. Man I feel tech today.

I have precisely the same Radio Shack Experimenter's Kit! Mine isn't so yellowed on the board, though. :-)

can u make a video...to calculate the value of the resistance needed in details. ....

This capacitance is like a capacitor has been placed between the base of 2nd transistor and ground, right?

Hi John i enjoy your videos, i have a request is it possible for you to do an ab output stage design tutorial?

OK. Just f2f the top of my head and when I get home ( a couple of weeks) j may try this... What if instead of a resister we used Shotsky diode?

Snickers, I want to pet you Cheers from Indonesia

4141? vs 4140

New clamp meter.... Awesome

it's there to enhance the bass

nice kitty soft kitty little ball of fur !

Lovely Kitty...!!!

FEELtech, is that a meme reference?

The usb thing is an FTDI chip

Yeah, should have remembered the devil of the collector to base capacitance, especially in power transistors. Reminded me of an older video you did on Baker Clamps: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dbi05EhAVVY.html

Therehould be two resistors .one in each transistor

As a postal mechanic I ask people not to send objects in plain envelopes(send as a package), as these object may get jammed in mail processing equipment and not get to their destination in one piece!

TKQ

First