Phototransistor Wiring Help!!!

Discussion in 'The Projects Forum' started by Chris15, Nov 4, 2009.

  1. Chris15

    Thread Starter Active Member

    Apr 15, 2009
    252
    0
    Hello
    in this schematic i have a photodiode, is this schematic telling me that i use the two outer legs of the 3 on the phototransitor, because it is not wired like a normal transistor, they don't show where the base goes?

    And a seperate question is IC 1 (LM567 Tone Decoder) a 8 pin IC just like a 555? it just because it is triangular on the schematic, that is confusing me, so does it still have 8 pins?

    Thanks, Chris
     
  2. Chris15

    Thread Starter Active Member

    Apr 15, 2009
    252
    0
    Here is the Schematic for my problem
     
    Last edited: Nov 4, 2009
  3. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    The LM567, I looked at the National Semiconductor site, is an eight pin package. It can be in a metal can, a DIP, or an SOIC.

    The phototransistor uses light instead of the normal input voltage at the base... Here is a good explanation. They often times do not have a base connection.

    http://encyclobeamia.solarbotics.net/articles/phototransistor.html
     
  4. Chris15

    Thread Starter Active Member

    Apr 15, 2009
    252
    0
    Thank you
    so just quickly, the phototransistors base for my circuit can be cut off, i dont need it just the emmiter and collector?, and the LM567, so it dosent matter which one i get the can or the DIP whatever that it, as long as the component says "LM567" and has eight pins thats the one i buy?

    Thanks Chris
     
  5. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    Yes, the base on the phototransistor is typically not used. I do not know exactly what part you are using or why the additional lead is still there. I usually leave the parts intact until I know the circuit works, then, cut away...

    A DIP is a dual-in-line package, it has 0.1 inch lead spacing. This one will have 4 leads per side. If you are building your circuit on a pre-drilled prototyping board, the spacing is usually 0.1 inch, so the DIP is usually the easiest to use. You have to bend all of the leads of the can to make things fit nicely, whereas, the DIP slides right in. The DIP is also big enough to make connections to fairly easily.
     
  6. Chris15

    Thread Starter Active Member

    Apr 15, 2009
    252
    0
    ok once again thank you so much
    So basically to make this thing work i just do everything the schematic says, if the triangular IC says pin 8 go here it goes there, and if the emitter and collector are onl used then only use them, However i have purchased a LM567 tone decoder and it looks like the 555 timer 8 pin black box, so is the tin can like thing the LM308? and also a phototransistor can be replaced with a photodiode the LED looking thing right?

    Thanks Chris
     
    Last edited: Nov 6, 2009
  7. kbirecki

    New Member

    Oct 22, 2009
    20
    0
    I can't answer your last question, but I did read elsewhere that if a phototransistor has a third lead, (i.e. a lead for the base), it is used to bias the phototransistor.
     
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