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  1. HellasTechn

    Help with A123 transistor.

    CORRECTION the pin connected to VCC is the left hand pin... its middle pin goes to pin 7 (GROUND PIN) of the same ic through a potentiometers middle (wiper) pin. the right hand pin goes to the IC's pin 12 (marked 6y on the datasheet) pin 12 must be an inverted output
  2. HellasTechn

    Help with A123 transistor.

    ok when faceing the flat (printed) side of the a123, its right-hand pin is connected to an sn74hc14n pin 14 which is VCC pin. so that i guess is the emitter ? then middle = base and left = collector ?
  3. HellasTechn

    Help with A123 transistor.

    There is no legend on the pcb indicating e,b,c positions, it only shows the shape of the component (flat side , round side). ***It just crossed my mind that i do have a few C123 transistors in my hand. Any chance that they could be complementary and have same e,b,c arrangement ?*** I cant do...
  4. HellasTechn

    what's this component??!!

    I see the diodes for the middle and right button... Culd you post the picture with the missing part in a red box ?
  5. HellasTechn

    Help with A123 transistor.

    that still does not solve my pin arrangement issue. Say i replace it with a close PNP like minder suggested, how can i be sure which pin is base, collector and emmiter since my part is TO-92 (not a TO-18)?
  6. HellasTechn

    what's this component??!!

    According to this site, the f1 (sod-123 package) is probably a zener diode. http://www.s-manuals.com/smd/f1
  7. HellasTechn

    Help with A123 transistor.

    You are right. My problem is that i am not sure if this damaged A123 is the same as the 2sa123. What troubles me is that i dont know its pin arrangement and even if it is a PNP indeed or not. It's probably the same but i just want to make sure...
  8. HellasTechn

    Help with A123 transistor.

    Thank you for the information ! I only have one doubt about the 2SA. becase of it's package. Like in the attached picture the one i have is TO-92. The 2sa123 and nte126 are TO-18
  9. HellasTechn

    Help with A123 transistor.

    Good day to all ! I need information on a transistor marked A123 (TO-92). Is it PNP or NPN ? it's pin arrangement or even better if anyone knows an equivalent. It was mounted on the control board of a refrigerator. i have no other info on that. Thank you all ! P.S. I found it on e-bay but no...
  10. HellasTechn

    Connecting up very small, curved pins.

    I agree with Audioguru, only above kind of chips are around ever since i remember myself (more than 30 years). I think this specific kind needs stencil and hot air station to be soldered. You could try soldering them directly on the PCB by creating a solder "hill" between the side of the chip...
  11. HellasTechn

    Component Storage

    That's exactly how i do it. and each little drawer is divided in 3 sections each holding a value range. then same value resistors i twist together and tag then with papper tape writinh their value on.
  12. HellasTechn

    Back diode

    biferi no offence but davenn and steve are right. More and clear information are needed bofore one can answer a question.
  13. HellasTechn

    Odd interference between electric heater and computer

    It is :)
  14. HellasTechn

    Back diode

    Probably, Minder.
  15. HellasTechn

    network switch in networking ?

    all switches use normal cables. Crossover cables can not be used with an ethernet switch unless it has a cable selector switch. Also i think crosstalk cables are also called null.
  16. HellasTechn

    Powering my IC

    I agree . The simplest and safest is an 7805 Vreg.
  17. HellasTechn

    Microcontroller debugging

    There are many free programs that you can use for that. I personally use Termite serial comm program.
  18. HellasTechn

    cctv re-wiring

    That makes perfect sense. as a matter of fact i was just about to ask you if your's have IR leds :)
  19. HellasTechn

    555 on/off circuit for 5v motor (w/ schematic)

    Good practice ! :)
  20. HellasTechn

    Can I store TV circuit boards in Ziploc bags

    True. I am just saying that if you already have both ziploc and foil.
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