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Everything posted by BasilBadger

  1. Sounds good, would you happen to have a name or a link? 8) All the best, Basil PS: I'm in Denmark
  2. hehehehe. Now, that's excactly how i'd describe my relationship with those too ;) Thanks a lot for bringing the PICAXEs to my attention. It looks like they have all i need: A PWM out and a RTclock/LCD add on. Seems, providing i stick with PWM, all i need to worry about is the powersupply and the driver section. All the best, Basil PS: Wifey is done testing and sorting the LEDs, result: 992 of 1000 LEDs are ok, which was a pleasant surprise, since they were a surplus lot of 1000 white LED (3mm 17,000mcd) for only $87+pp.... Sometimes you are lucky.
  3. For a dawn simulation i need to control all LEDs together, fortunately. I have been considering using current control, but i think PWM is easier to build. I'll only need one output, which will make wiring up the LEDs easier. Are there advantages using current control instead of PWM? I have some experience with the Parallax basic stamps, i've used them for making some tricky process controls at work. I must admit i hadn't thought of using them for this project. But i think it's a splendid idea. That way i can get wifey to both pay the parts and program the controller ;D (She is the computer nerd in residense, after all) and i wont get any complaints about the clock being difficult or awkward to set.... Wonderful, hehehe. All the best, Henrik
  4. Yes, i think i'll make series of six LEDs with a resistor on the tail, seems the easiest. A resistor for each diode seems to me to be a lot of work. Now for a power-supply; i have been eyeing all those old computer power supplies i have. Stacking two of those would provide a nice stable 24V. Any ideas how those would take having a PWM circuit loading them? Or should i rather build a conventional powersupply? I suppose a LM338 stabilised one would do just fine. I do have the LM338'ers in the junkbox. Then there is the PWM circuit, i'm leaning towards making it voltage controlled, since that would make it easy to switch between manual and automatic dimming. Any thoughts? What about the switching frequency? A kHz or so? I've disected an old clock-radio and have decided that it will do just fine for starting the "dawn". It turned out it was it's buttons that had died, digiswitches are easier to install in a panel anyway so that's no loss. Another piece to the puzzle is making a ramp voltage that will simulate dawn. Ideas, musings and downright "you are nuts'es" are most welcome. Please let me hear your thoughts on any of the above and (most important) what i have forgotten to think about All the best, Basil
  5. Hi all, My sweet wife wants a "dawn simulator" the ligthsource is to be LEDs, 740 of them in all....... I've tried to discourage her, but she seems to believe i can do magic with electronics since i built her an amplifier/mixer for her computer stack. I have been pondering how to drive those LEDs for some days now: 1: It seems, to me, that PWM is the answer. 2: 24V is max voltage i'll allow out of the controller. Any ideas and musings would be most welcome, as i'm still in the pondering phase. Just to prove her belief in me, the sweet one bought 1000 white high brightness LEDs of Ebay. To get me committed as she says ::) For revenge i have built a little teststand so she herself can pick out the 740 best of the LEDs , hehehe. Any ideas? Basil
  6. Hi, I had a somewhat similar problem where a click from a plastic coupling were to stop a test. The test machine was located in a production hall. The solution was to rectify the signal from the microphone to get an "average noise level" the rectified signal was "stored" in a capacitor with a resistor in parallel. As i recal the time constant was around 250msec. That signal was then fed to a differentiator, with a trigger circuit on it's tail. The idea being that a sudden increase in noise level would set off the trigger, not the general noise level itself. After quite a bit of fiddling with amplification and timing, the circuit worked really well. Hope that helps, Basil
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