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Transistor matching tester....help needed

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  • Transistor matching tester....help needed

    Hi,

    I am constructing a Bedini SG and need help with the transistor tester I have constructed it and the meter needle does not budge no matter where I have the pot set or with the 27k resistor bypassed. I measured the voltage between the push button switch and the base of the transistor that will vary between 12 volts and 11.70 depending on the pot setting. I even tried reversing the transistor and the needle will move and the transistor will heat up. I can take a picture of what I have built.

    Thanks

    Ian

  • #2
    Ian can you make picture

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    • #3
      Here are a couple of pics

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      • #4
        am having trouble uploading pics will keep tying

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        • #5
          I have tried again to post a couple of pics but I get this red icon come up......,some kind of error message what other ways can I send you a pic

          Ian

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          • #6
            transistor tester 1.jpgtransistor tester 2.jpg Lets hope this the pics tried another method
            Ian

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            • #7
              Ian,
              Sorry I can't help with your transistor matching but how did you fix your picture upload? I am having the same problem on my post.

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              • #8
                Hi Bob,
                Yes it was a bit of a pain for as I have not been on forums for a while click in the immage icon that brings up a box with options, in the bottom right hand corner there is a "basic uploader" that is what I ended up using.

                Ian

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                • #9
                  Testing upload pic

                  4Crun1charge.jpg

                  *Edit*

                  Many thanks Ian,,worked like a charm!

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                  • #10
                    Schematic1.JPGMJW21194-pinout.jpg

                    I cant tell from you pics but it looks wrong to make things easier ..leave out meter and push button switch
                    if you flipped the transistor it may be bad
                    i dont see a ne2 $(KGrHqJHJBgE8e6)BkfHBPJUnmo4z!~~60_35.JPG
                    more pics will be helpful
                    i dont see any diodes either
                    if you are building a trans tester then disregard all i said
                    i test trans with dmm https://www.youtube.com/watch?v=b0jCUsenNsY
                    if you have a diagram of what you are building post it
                    Last edited by guyzzemf; 02-14-2015, 03:10 PM.

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                    • #11
                      I have tried a number of different new transistors transistor tester 2.jpg the diagram is in the bedini manual

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                      • #12
                        P2150001.jpgP2150001.jpg previous was wrong pic

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                        • #13
                          iv never built that. it looks straight fwd ck a few transistor with d meter ck ur build/ then with a good transistor ck build
                          be sure u build it exactly as it is ,use cheap transistors
                          do u need to match gain for a multi transistors build ,if u havent built a single transistors [1 power 1 trigger] ssg yet [u should ]
                          if u just need to ck trane use dmm


                          https://www.youtube.com/watch?v=JLXKffm7VF4

                          https://www.youtube.com/watch?v=BgT9-VRf1Cw

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                          • #14
                            I began to experiment substuting resistors instead of the pot and found if I had a resistance of 19k the meter would give a reading of about 40ma if I went a couple of thousand ohms each way needle of the meter droped way back to very little. seems to be a narrow sweet spot.
                            Ian

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                            • #15
                              IAN
                              There are many diy transistor testers out there with instructions ,or for sale cheap
                              i have no experience with transistor matching . but i hear you will go through a lot of transistors to get a few that match
                              guy

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