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major basic stamp 2 homework baord power supply help — Parallax Forums

major basic stamp 2 homework baord power supply help

zemkaczzemkacz Posts: 19
edited 2007-11-04 13:12 in BASIC Stamp
as u know i am using a bs2 hw board, but i am using a servo, 2 leds, a photoresitor, and a number display, which is draining my batteries like crazy, so i thought about adding a soler panel, but they are all too expensive for 6v at udleast 100 millamps, so i then thought about running the servo using a h-bridge and a seperae battery for the servo, but the h-bridge are too expensive for 2 controllers (planing to put in another dc motor and switch the servor for a motor when i get another idea for power supply), and a h-bridge uses too much io space, but i only have 3 left, an now i found a small nicd pack thats 9.6v, but i dont know how much milliamps is gives, it looks like it has 8 double a bateries, the chargers is 12v 200ma, so i was thinking about instead of putting the 9v batter their, i would put the 9.6v nicd battery pack their, since the bs2 has a voltage reg, so i dont think i will make anything catch fire or something, what do u think i should do?

Comments

  • sdysdy Posts: 40
    edited 2007-11-03 19:44
    It's mainly the servos draining the batteries. This is what I do: I use a 7.2v nicad pack. I plug it into Vin and Vss. That supplies input power to the stamp's regulator. Also from Vin, I connect the servos V+.(actually thru a small switch so I can shut off servo power and still have stamp running). I recharge the nicad as needed.
  • zemkaczzemkacz Posts: 19
    edited 2007-11-03 20:17
    but is this safe? will is desryo the regulator or make it heat up to crazy temps? since i am really nto this already bt idont wanna destry the stamp by any chance
  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-03 20:20
    There are two reasons for not using a 9.6V battery pack:

    1) The higher voltage will damage the servos (shorten their life). Best to use no more than 7.5V on standard servos.

    2) Anything over about 6V is extra heat dissipation for the Stamp's voltage regulator and it doesn't really have a heatsink so it could run hot. If it gets too hot, it shuts itself off until things cool down ... not what you want.
  • RDL2004RDL2004 Posts: 2,554
    edited 2007-11-04 13:12
    If you go with the 7.2 volt pack you'll be okay.

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