Transistor tester

[audioguru2]

Steven, your circuit is very similar to this one.

This project's corrected schematic is here:

View attachment 35771

 

[MP1]

Like I said in an earlier post:
Read ALL the posts on the subject.... Others have commented changes that they made and mixos has even posted some changes in bold red lettering.

MP

 

[audioguru2]

MP,
The only modification that was successfully done to this project was when Mozikluv replaced its 555 and 4027 with a 4093, similar to Steven's transistor multivibrator.
Mixos posted a successful "change" in bold red lettering that was to connect the ground (pin 8) pin of the 4027 to ground (as on the schematic), Duh!
Most of the posts say that one LED is continuously on, because the flip-flop isn't being clocked due to the error on the schematic.

 

[steven2]

audio guru my in circuit transister tester dosent use intergrated circuits and i think the circuit i use works by shorting out the leds, something like that and the less parts it uses makes it really easy to biuld. mine works great .and gives great indication of any shorts between any legs of the transistor you test. its easy to revers engineer to.

 

[audioguru2]

Hi Steven,
Your transistor multivibrator is the same basic circuit as this project that uses ICs. The transistor being tested shorts its LED.
Just think how poorly it would work if one transistor's emitter wasn't grounded so that it wouldn't oscillate, just like this faulty project.

I like yours because it is cheap and simple. If it was a digital document instead of its fuzzy photograph or scan, I would post it here again, for all to see.

 

[steven2]

here it is the in circuit transistor tester. ill re photo the circuit better and put it in as soon as i find the circuit

View attachment 35773

 

[audioguru2]

Hi Steven,
That's a good looking kit and it has a strong case.
I also like your grip clip thingys. I had some that got worn out, but I haven't replaced them yet because I can't figure out how to take apart the new ones.

 

[steven2]

audio guru those clips are push down types that has a coper hook thing that enables me to clip them onto the transister legs, and if i test the 2n3055 npn transistor, because it only has 2 legs and the body is the collector i just push down on the third clip and touch the coper hook to the body of the transister to test.

 

[steven2]

View attachment 36057

 

[audioguru2]

Hi Steven,
Sorry, but its switch is labeled backwards. It is shown in the "NPN" position (NPN emitter-follower).

It is a waste of a 9V battery since most of its voltage is wasted in the 470 ohm current-limiting resistor. It could use cheaper and longer lasting two AA cells (3V), if it was rewired to be common-emitter, and its LED current-limiting resistor value decreased to match the lower voltage.

 

[steven2]

thanks audio guru i just uploaded it from my collection of circuits i collect off the net

 

[Dazza]

here it is the in circuit transistor tester. ill re photo the circuit better and put it in as soon as i find the circuit

Steven, I would really like to put that transistor tester together 8). have you already posted the circuit for it somewhere, or are you still, to find it to post .

 

[steven2]

mozikluv which transistor tester are you refering to ive uploaded 2 i think but the one i biult from a kit is the best one to biuld as it works by shorting out the leds

 

[Dazza]

Yes steven, the one you posted from a kit ;D.

 

[steven2]

dazza have you allready seen the posting of my in circuit transister tester i uploaded before, it works really good to, not bad fro a kit,

 

[Dazza]

steven, it looks good. But I want that Dick Smith one ;D ;D, or is that it you posted on this page

 

[steven2]

dazza i posted that dicksmiths one a while ago if you cant find it ill find it for you

 

[steven2]

its under the topic in circuit transistor tester, dazza

 

[steven2]

page 3 of electronic project/ design ideas you will find my in circuit transistor testor the dazza

 

[Dazza]

Thanks steven, I found it .