Search results

Search Forums New Posts
  1. C

    Any idea what this is?

    Even if you had of been in a betting shop, i doubt you'd have seen one unless you were in the 70's or 80's :p
  2. C

    Arduino + Relay(220V) Problem.. Need Help!

    It was 3am about to fall asleep.. The diode which acts as a flyback (negative voltage spike) to ground, so the transistor is not damaged In my head i was just thinking of ways to supress the voltage spike, a zener might be any good but it will supress higher voltages being induced back into...
  3. C

    Constant Current LED driver for "Varying Input Voltage"

    At 50v the Transistor dissipates 15w Ay 15v each tip will disspate 5w The lm317 will barely get warm.
  4. C

    Constant Current LED driver for "Varying Input Voltage"

    No, the lm317 won't heat up, it's offloading the current onto the transistors.. Look at the circuit i designed carefully
  5. C

    Successful monitor repair

    I don't mind, i rescued a dead samsung 40inch lcd/cfl tv someone threw out! 12 months later still going :D
  6. C

    car power circuit thingy

    Switching regs have an internal temp sensor, which limits the current... If they both fail? Add a fuse, if you want to go one step further, buy a thermal fuse! - i have these running 24/7 in my home i even beat the crap out of one, all the flux bubbled, so much heat damage looks bad, still...
  7. C

    Led charger indicator

    I still prefer a voltage comparitor circuit :)
  8. C

    Need help with battery power for my project

    Ahh, i never looked at the datasheet :)
  9. C

    car power circuit thingy

    Why not? Even an lm2596 will use a few ma in stand by, putting it another way The car battery will run it for months!
  10. C

    car power circuit thingy

    Look, the switching reg uses little in standby mode.. Use a 7805 to the pic from the sw/reg to power it Obviously some kind of script initiates after 20 mins or so, this will trigger an interrupt on the mc which powers off the pi... I don't see a problem
  11. C

    Led charger indicator

    There's a slightly easier / cruder way simply by using a zener diode..
  12. C

    Need help with battery power for my project

    Use a small 2n222/generic npn infront of the tip in a darlington style combo
  13. C

    car power circuit thingy

    No, i'm just confused as to what you want and what it it's already doing...
  14. C

    car power circuit thingy

    And offending project? I want to know why it can't shutdown when finished with the scripts
  15. C

    Arduino + Relay(220V) Problem.. Need Help!

    Stick a bigger cap on your 5v arduino, a zener across the transistor... i'm going to have a look into this tomorrow and do some tests
  16. C

    Arduino + Relay(220V) Problem.. Need Help!

    I seem to recall having issues doing this even with a diode in reverse, i can't remember if an optoisolator did the trick Having said that, it must have or the Christmas display would not have worked lol
  17. C

    HELP!! TV Fault!! Photos Included

    10 flashes would indicate a 5v working rail to the main board.. You need to test for shorts across those transistors, but before you do, carefully power it up not touching anything unless you wish death. . Then measure all the voltages going to the ribbon cables, but those 10 flashes are a clue
  18. C

    car power circuit thingy

    So what determines shutdown? Why not shut ut down then?
  19. C

    Constant Current LED driver for "Varying Input Voltage"

    Replace the constant voltage 12v (sim says 14v) source with an lm317, then vary the voltage (So your 12 - 30v into the lm317, the 12v out to the tip31)
  20. C

    Constant Current LED driver for "Varying Input Voltage"

    A tip31 to offload the linear regulator, and then a resistor.... 60ma? I thought you want 1amp? Maybe i misunderstood..
Top