Transistor Tester + project site coming soon

Design Concepts
1

Hi,

     This is to let people know i will shortly be putting up a website with a number of projects that maybe of interest to people here. Along with allsorts of misc content too !

     There are two projects in detail, to be put to web-paper very shortly. The first is how to adapt those multimeters with capacitor/inductor/transistor test sockets - so that they are far more useable. Notibly on de-soldered components with short leads ! …this consists of making up a probe set. ..theres a little more to it than that though.

     The second, and probably most interesting to those who repair equipment - or like to test their stock of silicon. Is a Simple Little device which can turn a Oscilliscope into a Function analyser for transistors, fets, diodes, bi-polars ..etc.

     This is based on a design found in a mid 80’s edition of ‘Practical Wireless’ magazine.

     By observing the results on the scope, the device type, condition & any faulty (even slightly fried !) devices can be diagnosed easiily ! Also in combination with a transistor testing multimeter - the exact pinout (b-c-e) can be worked out.

     Additional to this, i have built into this project a module to make also serve as a mini bench power supply suitable for running midibox stuff when it is on the construction bench. This Part will Supply -15v(unreg) -5v 0v +5v +8v +15v(unreg) - The output of this supply - per the components i used; shall be good for upto 1 amp on both the negative & the positive rails.

     Below is a picture of the tester driving a scope with a mosfet in circuit - result displayed on scope.

The box in question is directly below the scope, the 6 holes on the right are waiting for the power supply section to go in sometime later today. Most of this project was built from spare parts for nothing ! ..though i did pay for a new box, switches & connectors.

     This device earnt a proper project box after being built to test 50 or so signal transistors in a 3.7kw c-audio amp. ..which of course it succeded in finding the 14p culprit which brought the whole amp down !

Hope you guys enjoy this project & others to come soon !

Note: also on the books are some subwoofer & cab designs which have been built and tested…

Artesia.

2

Hey Artesia

wow, wow n wow again… :slight_smile:

this all looks fantastic - can’t wait to peep the project pages when up n running - testing/analysing is summin I really need to get to grips with!

and the speaker stuff too - great stuff all round!

Nice1!

3

Sweet!Can’t wait to see it!

4

http://homepage.ntlworld.com/nausicaa.valley/INDEX.html

Site now up in a fashion, a proper web address will be created shortly. The first revisions of the multimeter & transistor analyser are up now.

Enjoy :slight_smile:

5

Website updated again, added a batch of links (got to tidy that up somewhat) - and also have put the first bits of the thoughts/tips/rambles page up.

6

Congratulations for such a fast web site! There is no time anymore to walk for a coffee before the next page wakes up. It clearly shows again that super trouper graphical toys are not always the best solution, but simple text based layouts are much faster.

Cheers,

Skunk

7

Thanks for the feedback n’  enthusiasm skunk, d2k & arumblack :slight_smile:

Now added a quick test of a really, really simple flash image browser - got a couple of photo’s i took up  as a working example of this. There’ll be a large quantity of my better photos going up for easy public access - Now that i can to some degree stop my images being google-grabbed (the image search) & stop the average joe nicking off with them without any consent. however any pc tecchie would not have a problem getting the images out; anyone who knows that much, will probably treat that content with some degree of respect :slight_smile:

Will also adapt this idea for allowing easy viewing of the circuit diagrams within the website frame - so they can be viewed with clarity immediately on the spot.

When i work out how to get circuit diagram vectors into flash - this should be lightning fast & infinately zoomable.

8

Nice site  ;D

Maybe I’m blind, but, I can’t find a link to this forum nor ucapps.de ?

Just a thought…

/Wise

9

Indeed you are right wise :slight_smile:

It had crossed my mind; after the last time i had updated the site. most of it is somewhat under construction atm..

10

So this is a curve tracer or something?

Bye, Moebius

11

Hi,

had never heard of a curve tracer uptil now :slight_smile: Just looked some up on the web with ol google. Its not quite a curve tracer; but it works a little like one. unlike the curve tracer the feed signals are shifted by 90 degrees which provides a different ‘angle’ on the diagnostic process which is better suited to testing  the behavior of semiconductors. The curve tracer seems to be geared primarily to identifying passive components. Having said that it’d be handy to expand the concept Ive been toying with to include the basic curve tracer function also …watch this space.

The first curve tracer site i saw was this one:

http://www.techlib.com/electronics/curvetrace.html

the second was this; seems they had the same idea i did about building in a power supply :slight_smile: :

http://www.fullnet.com/u/tomg/gooteect.htm

(nice looking project this one)

Update:

Had a look and a think on the matter of including the curve tracer function - it could be done easily with a switch (or two). Since this’ll make it into a fairly universal tool - ill get onto the matter within 24 hours. will make and test this idea & include the tested revision as a MK II version. will be testing all components thouroughly soon.

Thanks for pointing those devices out moebius :slight_smile:

12

sweet! especially like the rantings in the “thought’s tips rambles” section…I have had some of the same thoughts myself(  especially the tv shows, and hifi ones). keep up the good work!

13

Man, that  looks like a neat little project to work on after I’m finished w/ the project I’m working on for school.

Question: Where did you get the neat little enclosure for the transistor tester?

14

:slight_smile:

Hi,

      The little box the unit was put into, came from maplin & cost under £3 ! ..wasn’t  even worth gettting the sheet metal bender out to make one for this project  :slight_smile: Will get round to adding parts lists for those projects. soon.

      Also a hybrid between a the Transistor analyser & a curve tracer has been concocted - however there’s afew errors on the draft circuit diagram on the site right now - i will correct that soon & modify my tester for the dual functionality & report back. This will allow even greater flexability for analysing components. Though get ready to solder up a hell of alot of switch contacts  ! :wink:

      Additionally - have added to the ‘Thoughts/tips/rambles’ section - ‘‘store cards & rfid tags’’ + ‘‘a hoarders paradise’’.

      i’m thinking to myself here atm - that i should relocate this thread to somewhere appropriate for announcing website updates ? ..or just keep here for now ? …hmm

Anyways - enjoy :slight_smile:

15

Hi,

      Neearly there with the dual function version of the analyser - will finish the hardware version shortly.. got distracted wallpapering & plastering here :expressionless: :]

      Also, could not figure out a way to switch between curve tracer & semi tester without using a minimum of 5 switchover poles. Which means that there is a 4gang switch + another relay. When i update this project.

      I will be offering a free cd album (of your choice) in a challenge to find a perfect way of switching modes with only one 4 pole switch :slight_smile:

      Also - a new project which i’ll look into getting done this month;

      Is a project to turn almost any PC Soundcard into a Basic Oscilliscope & benchtop Function Generator/Signal Source. This would be afew Good Quality opamp circuits which would allow flexable performance in a DC Coupled configuration.

      This would of course offer a cheap & effective way of using the component/semi tester without having to own a ‘potentally’ expensive oscilliscope first

      Also of course it could in theory be used for general mesuring upto the soundcards bandwidth (16,000-22,000Hz normally). & as noted it should serve quite well as a signal generator / source. & if you are into messing around with lasers like me - it makes a great way of computer controlling dc servos in order to animate laserbeam scans on a budget :slight_smile:

      Anyways will be back  to report that the page has been updated with the new tried & tested analyser  revision  :slight_smile:

16

Hi Artesia!

Why don’t you leave out the relay and use an multi-deck rotary switch instead? For example a switch with two layers of 4 poles. Those switches are easily limited to only 2 switching positions.

Regards,

Dr. Nick.

17

Hi Dr Nick,

      Havn’t used rotarys yet due to a compact design here - am using a 4 pole toggle to switch modes. problem was i could only do it with 5 - then i spotted a oversight & i think i can get it going on 4 fine anyhow - and thus ditch the extra relay.

      Going to go tinker with the project again now ive figured out somthing else i overlooked - hopefully next post will be to announce that a working revision is on the site & tested.

Having said that - roatarys would come in handy for one thing; extra value settings.

Update:

      Just upped a corrected version of the tester schemetic - should work, though having abit of a job getting it working on the bench - with the right rats-nest of  wires ! …this is almost a pcb job.

Update #2:

      Got it working !

However currently in curve tracer mode, need to set one of the channels to .5mv/div whilst the other is at 5v/div (this will be due to one channel working in a weak ‘current sense mode’). will try to tweak / add some more resistor networks to allow changin between modes -  without  having to change oscilliscope ranges everytime.

Update #3:

      Tester now fully reassembled - power supply section now installed. Works nicely :slight_smile: However have not been able to easily balance output levels to the scope with circuit tweaks. Turning out to be more complicated than expected. Will probably impliment that at a later date by setting up a transistorised gain circuit to balance outputs correctly.

      Tonight i’ll add the updates on the site

      If you are into repairing stuff in particular - have a go at building this; probably the most useful tool you’ll ever have ..after the multimeter of course :slight_smile:

      ‘User Manual’  to follow  in a week or so…

18

All details for the working hybrid component/transisator analyzer are up now. also included a basic circuit for a curve tracer too.

New pictures + diagrams  added & such…

…anyways - Finished working on this project for  now  - goning to go and fix some stuff with it  instead :wink:

More stuff sometime soon - on a different thread i expect.

19

So any pointers on a decent (cheap!) scope? I think its time I got one…

20

Hi d2k,

Not quite where to advise in general - i tend to pick  these sorts of things up at amateur radio shows for cheap. Got the 1980’s one i have for a tenner ! (350mhz & still worth £500 second hand ;)) - ex batch uni stock; the guy thought they were all knackered. It just had some dirty switch contacts :slight_smile:

…can pick up scopes working second hand at these shows from between £30 to £250 or so - depending on specs. For most electronics work we do here (non-rf & radio) - scopes starting at the 10-30mhz margin will work fine; anything else is a bonus. Though - look out for a X-Y plotting mode for using the scope with this project :slight_smile:

afew elecronics places do handheld 10mhz  lcd scopes for £100 or so - would’nt reccomend them from what little experience i have of them. CRT scopes seem more responsive & finer in resolution.  Keep an eye on the various second hand outlets & such i guess.

Depending on where you are located - i maybe able to point out some places that deal in surplus equipment & stock…

if in uk check out these people for second hand / refurb:

http://www.stewart-of-reading.co.uk

They do a kenwood & gould  for £95

…though id have to say, rather awkwardly - the best place for most people to pick up a scope is ebay.