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Stamp power supply — Parallax Forums

Stamp power supply

erastuskerastusk Posts: 17
edited 2009-03-06 09:56 in BASIC Stamp
I'm trying to connect a stamp to a breadboard with an AC 6-9V adapter plug.So i assume i'll use VIN that way i can use the stamp's regulator to get 5v.
1.Does anyone know what polarity i connect to VIN.(Plug has 3 prongs).I blew one stamp already.
2.The adapter plug has 3 prongs..so i should connect the ground pin to VSS right?



Thanks

Comments

  • Scott2HotScott2Hot Posts: 10
    edited 2009-03-03 12:52
    Is the output voltage is AC or DC?
  • Mike GreenMike Green Posts: 23,101
    edited 2009-03-03 14:06
    Can't tell from your description except that 6-9V AC applied to a Stamp will fry it.

    Vin on the Stamp has to be connected to a positive source of 6-9V DC with the negative source connected to Vss (Gnd). The voltage source should be able to supply at least 50mA.
  • erastuskerastusk Posts: 17
    edited 2009-03-03 16:24
    Hi Mike,
    Currently I'm using an educational serial stamp board.I"m using the adapter plug that comes with it.Input voltage is AC, DC output.I"m trying to transfer the whole setup to a
    PCB and was wondering how to do it.
    +ve to VIN
    -ve to VSS

    thanks
  • ercoerco Posts: 20,259
    edited 2009-03-03 23:01
    It's usually wise to add a 100-1000 uF electrolytic filter cap in parallel with your DC input (watching polarity) if you're building your own PCB. If you have a lot of extra circuitry that needs 5V power, keep in mind that the Stamp's built-in regulator can only deliver so much. If you need much more than 50 mA, you should have a seperate 5V regulator (7805 or better) to power everything including the Stamp. In that case you will feed the regulator's 5V output (again, with a filter cap) into the Stamp's Vdd input.

    If you're including any relays (or other noise-generating devices) on your PCB, locate them as far from your Stamp as possible, physically and electrically, to minimize interference which can cause erratic operation.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"If you build it, they will come."
  • erastuskerastusk Posts: 17
    edited 2009-03-05 23:38
    Hi Erco,
    I'm building a small IR receiver so all i have is the IR Detector and resistor..5v from stamp should be enough right?
  • Mike GreenMike Green Posts: 23,101
    edited 2009-03-05 23:56
    You didn't say how much current the IR receiver takes. It's probably fine. The one that Parallax sells takes at most 3mA and has its own built-in pullup resistor. Remember that other things like LEDs, relays, and LCD displays take power as well
  • erastuskerastusk Posts: 17
    edited 2009-03-06 02:57
    Yes i'm using the parallax one, i have nothing else on the PCB
  • ercoerco Posts: 20,259
    edited 2009-03-06 05:49
    erastusk: You're golden! Just go slowly and double-check all your power connections as you make your board. Obviously you know to use a socket for the Stamp. Solder the empty socket and other connections, apply power and recheck connections before switching off and plugging the Stamp in. Tune for minimum smoke! When you apply power with Stamp installed, feel the Stamp and kill power if you feel anything warm.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    ·"If you build it, they will come."
  • erastuskerastusk Posts: 17
    edited 2009-03-06 09:56
    Lol.Erco thanks for your help as as always.
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