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steven

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Posts posted by steven

  1. :)in these latest pictures, ive been busy decorateing these circuit boxes , with green pvc cut from green colourd storm water pipes, about the thickness of a match stick, all of the pvc i used to make my home made circuit boxes are about the thickness of a match stick or just under. in the pictures the bottom circuit box is yet yet to be dressed up and other ones sitting on top of my wardrobe to. thr green pvc i used to dress up my circuit boxes sure makes the knobs and ic stand out really good.

    post-876-1427914176315_thumb.jpg

  2. :)poonam , black rectifier diodes have silver band marking the negative end .1n914 and 1n4148 diodes are red or pink colour and have a black band at one end marking the negative end . and i have a diode looking component with blue band in middle, its a diac as for zener diodes i have grey with black band at one end .and i have yellow ones with black band at one end , to me the colours mean nothing but the details or numbers on the side when i check them up tells me what voltage rateings they are etc etc

  3. :)in the circuit above the the 2 diodes on the top left next to the 18 volts positive input, part number rs 276-1101. the resistor on the right near it is 150k on the far right nextr to output is 480 ohms 1/2 watt resister and under it is a 10 uf tantulum capacitor
    near that to the left is 5.6k resister with red led and earth .on the right hand side of the 20k trimmer is 70k resister.capacitor at pin 5 is 0.01uf 25 volts polycapacitor between pin 5 and 6 is 2200p.
    tune the trimmer for 2128 hz.

  4. :)in the poor quality scanned image the 2sc indicates that the transister is a high frenquency npn type .
    b-japeneese [EIA] or american[EIA]
    c- the transistor application and whether it is an npn or pnp type.
    2n-transistor,FET,SCR,or triac.
    2SA-TRANSISTOR,HIGH FRENQUENCY TYPE,PNP TYPE
    2CB-TRANSISTOR, LOW FRENQUENCY, PNP TYPE.
    2SC-TRANSISTOR, HIGH FRENQUENCY , TYPE.
    2SD-TRANSISTOR, LOW FRENQUENCY, NPN TYPE.
    2SJ-FET, P CHANNEL.
    2SK-FET, N CHANNEL.
    3SK-MOSFET, N CHANNEL.
    3N-MOSFET, DUAL TRIACS.
    4N-OPTO DEVICES.

    by looking at the transistor number, you can determine if it operates at a certain frenquency and whether it is pnp or npn type. the suffix letter after the last number indicates an improvement over another transistor. note that the b or c suffix letter aftre the number indicates a much superior transistor than the letter a.
    if no numbers are found on the transistor, measure the supply voltage on the transistor, determine what type of circuit the transistor works in, whether it is high or low frenquency, and if it is small, medium ,or large power by the use of the transistor case.

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