Thanks Paul. That's a pretty easy way to identify a BJT. I just use my Peak Atlas DCA75 Pro.

Thanks Paul I'm really getting a lot from your channel ,thanks again.

Nice quick check. I did not know about the difference in the emitter/collector. Thanks Paul.

It's always important to know how to identify a tran

@SimpleEnough2k9

6 жыл бұрын

..."identify a tran"... Hummmmm.... Beside the fact they also do have three legs, you're not talking about the ones that can walk, do you ? ;-)

@ianbertenshaw4350

6 жыл бұрын

Digger D Checking the bush for a twig and berries !

Thank you, good video; we need a video of how to cross reference to get the right transistor.base on characteristic of the old transistor. Can't find any video that show how to.

Great tip Paul. I didn't know you could do this with a DMM. Though I'm glad you sold me on the idea of the component tester l0ong ago. I use mine all the time, my eyes aren't what they used to be so it's easier to use than trying to read numbers or color codes. Thanks for the very useful tip and uick video!

@robertcalkjr.8325

6 жыл бұрын

You can use a VOM with X10K also, but it's a little more involved.

Excellent.

Another great tip very well explained for us beginners Paul, thank you sir... 👍🏻 🧐 🐍

I recalled reading a text mentioning that the voltage drops were slightly different although it was a little while ago. You nevertheless have to pay a close attention to the component you're testing, specially for the beginners, since you can have different type of components using the TO-92 casing. For instance, you can have BJTs, FETs, regulators, temperature sensors, etc..., therefore it would be strongly suggested to read the inscriptions on the case and download the corresponding datasheet to determine what type of component you're dealing with. Based on that information, you can then proceed with your DMM and perform the procedure suggested by Paul, whenever applicable. The datasheet will become handy if you happen to have values that are way off which would potentially indicate a short or an open junction, knowing that you're probing on the proper pins. Even if this is a basic concept, it's always interesting to put our acquired knowledge to practice and "visualize" what's going on.

Neat and good to know; even if i prefer the LCR-T4.

Always good to know..

Cool. Thanks boss.

I have a notebook I been adding to for the past 15 years.. I also ordered that component tester 3 separate times and all three never arrived, the sellers disappeared from eBay and eBay was not helpful at all in getting me a refund. There were like "Oh well" and never responded back since. So I just stick with my method of looking them up online and making notes in my notebook. Just be careful ordering those testers, there are a lot of frauds out there.

@Venomator.

6 жыл бұрын

ElfNet Designs Suggest using Amazon for stuff too dodgy on FleaBay - at least if your gear doesn’t show (which is rare in my experience!) Amazon will intervene. Purchased x3 component testers via Amazon and all three arrived - although one was broken and the seller gave an instant full refund, can’t complain about that? ... 👍🏻 🧐 🐍

Great explanation Paul! I really like this simple example. For some reason I always had problems understanding transistors. I treat them as gates/resistors, which in case of NPN are triggered by a high state, and in the case of PNP - low. But I always have to check if the LED must be on the collector or the emitter side. I noticed that depending on the type, the current passes from the emitter to the collector or the other way around. Why it can't be consistent, is beyond me...

@robertcalkjr.8325

6 жыл бұрын

en.wikipedia.org/wiki/Bipolar_junction_transistor

Everyone should know how it should be done .... and be able to do it ... Simplest solution is to make certain to get a component tester ASAP and then ensure it is batteried up and in your bag at all times. Might not be the most accurate in terms of absolute values but as a quick method for sorting out a box of bits it's worth every one of the £7 I paid. The little holder clampy thing is much easier than juggling small components and fiddly clips. As I'm getting older and components are getting smaller, the value of decent clamping, holding and magnifying systems is becoming more important for everyday work. So is identifying nondescript blobs of plastic and metal. I recently found a combination forceps/tweezer that's actually able to hold components down to 0402 quite securely ... and found an electrical tweezer probe attachment that plugs into a meter. I'm still tiddlywinking resistors into infinity - but not as many and I usually know what resistance they were.

Why does the Base to Emitter forward base has more of a forward bias voltage compared to the base to collector?

Great wee tip for newcomers who don't have a component tester yet!

@Elfnetdesigns

6 жыл бұрын

Those testers seem nice but, you need to be very aware where you order them from. I ordered the same tester from 3 different sellers three different times and I never received one tester. eBay support is useless and the sellers have long since disappeared from eBay with my money.

@gartmorn

6 жыл бұрын

@@Elfnetdesigns I have had countless dealings (100+) with Chinese sellers, mostly banggood and IC station, and only had one bad experience (an eBay seller)! I would certainly be wary of parting with large sums of money but my overall buying experience has been very positive. I have heard British customs have been clamping down on Chinese sellers who put low prices on packages to avoid import duties but that is a recent thing I believe!

@robertcalkjr.8325

6 жыл бұрын

ElfNet Designs I have 4 Peak Atlas meters and have never had a problem with any of them. Plus it's kinda cool having something that says, "Made in England" on it.

@gartmorn

6 жыл бұрын

@@robertcalkjr.8325 I once got a couple of buck converter modules from eBay and noticed on one of them that one of the electrolytic capacitors was hanging off! I looked up the order to put in a complaint only to find I had only ordered one! The cap was an easy fix so I wondered if they put the extra module in as a bonus knowing the buyer could probably fix it? It would otherwise have been binned I suppose. Or not!

@robertcalkjr.8325

6 жыл бұрын

gartmorn Yeah, they know that most of us will just fix it and not waste time complaining. I think that sometimes they do it to test us and see if we can fix it.

Hi, exellent video, I didn't know that you can identify Emitter and Collector by their foward bias voltage. Do you have any tip in how to test if a phototransistor is working?

@learnelectronics

6 жыл бұрын

Same way. Connect positive to base, negative to collector should see about .61xx then connect negative to emmiter should see about .64xx.

@robertcalkjr.8325

6 жыл бұрын

Plus, you need to make sure it is a phototransistor and not a photoresistor.

Can you point me to that component tester?

*Are you familiar with old valve tubes? Can you make some videos on it. I know tubes are history now but still would like to have video on it.*

@learnelectronics

6 жыл бұрын

Im not a tube guy, sorry. Try Mr. Carlson's Lab on KZread.

@pankajroy5124

6 жыл бұрын

@@learnelectronics it's ok. You make wonderful videos and I love your videos.

@ianbertenshaw4350

6 жыл бұрын

Pankaj Roy Also look at uncle Doug channel he made some nice videos on how valves work and his channel is mostly dedicated to valve amps .

All well and good, but how do you figure out the Beta, FT, Cbe and Cbc ? You can't really do much with the transistor until you know those parameters. Thanks for shareing

@learnelectronics

6 жыл бұрын

The video was how to identify, not how to characterize.

@robertcalkjr.8325

6 жыл бұрын

I can hook my Peak Atlas DCA75 Pro to my computer and graph them. Works great!

Great video. I'm learning something new everyday. Can a 555 timer be tested in a similar manner? Or do I need to buy a ic tester?

@learnelectronics

6 жыл бұрын

I dont know a a way to test a 555 with a meter.

@SimpleEnough2k9

6 жыл бұрын

The "easiest" way to test a 555 timer, in my opinion, would be to create a basic circuit as a led blinker. Simply use a DIP socket for the 555 you want to test. Turn it on and voila, you have a visual confirmation if the timer you want to use is working or not. If you're planning to built quite a few 555 timer based projects then having your own homemade "tester" might be a nice to have.

@MrPenguin098

6 жыл бұрын

@@SimpleEnough2k9 Thank you. I'm new to electronics and I appreciate the help.

@robertcalkjr.8325

6 жыл бұрын

Armando Perez Breadboard it. Datasheets usually include test circuit schematics in them that you can use to test components. Sometimes I Breadboard components just to play with them. That's how I discovered that a 555 can be controlled by resistance through the #4 reset pin.

@MrPenguin098

6 жыл бұрын

@@robertcalkjr.8325 Thank you very much. I will breadboard it. I got a schematic from Google for the 555 timer.

OL stands for over limit.

N P = positive base N P N = negative base P Pretty easy to remember eh ! Now what if you have a to-92 device that has no markings - it could be anything , a mosfet , a darlington , a unijunction , a regulator , a hall efect sensor or even an old mk484 radio chip . Is there any way to identify some of these ? Radio chip would be a problem and the hall effect i'm not sure about . I also have one of those little testers and for what they cost they are worth their weight in gold !

@robertcalkjr.8325

6 жыл бұрын

"injunction"?? Do you mean a PUT, Programmable Unijunction Transistor??

@ianbertenshaw4350

6 жыл бұрын

Robert Calk Jr. Yes damned spell check has changed what i typed to what it thinks i typed ! I have edited my post to fix it .

@robertcalkjr.8325

6 жыл бұрын

ian bertenshaw Oh, ok. I was wondering because it seems like most people have forgotten about PUT's. Even my Peak Atlas DCA75 Pro can't recognize a PUT. I talked to a person at Peak a couple of months ago and asked them if they could update the DCA75 Pro for the PUT. Hopefully some day they will.

Yeah, you do not want to find out the hard way!

how do you know that the bigger resistance is the emitter because you can flip it around and it'll be collector though.

@learnelectronics

6 жыл бұрын

No it wont