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  1. C

    detection of voltage in faraday induction by arduino

    Without more info, you could try an inductor, however depending how strong the mf is, the induced voltage might be small in which case you may need to amplify the signal before passing to an input pin...
  2. C

    toggle LED using momentary push buttton

    A mechanical push switch relies on 2 metal contacts touching, in computer terms it will show many button presses from 1 real press.. 1. In your code simply wait until contact/button Is pressed and wait about 300ms or longer so that the button is not touched by the end of the delay... 2. A...
  3. C

    lasers power supply problem

    My money is on it drawing more current than it should and you're hitting 1amp+ Got a multimeter handy? Measure the current draw.... ?
  4. C

    Remote switch

    Any old relay will do the job providing it's wattage rating can handle the speakers rating... unless the school has rock concert speakers you'll be fine... Then 5/12v power source will connect your speakers up at a touch of a button, however you will need a power source to energize the relay...
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    20 Watt LED Dimmer Circuit diagram

    Even with a 555pwm setup, this won't work with 12v He's using 20 one watt LEDS, that's quite a foward drop, you'd need to supply a higher voltage and then regulate the current.. Keeping in mind 555's get temperemental over 12v (the Chinese clones are lucky to work over 10v)
  6. C

    Pionero VSX 1021 K Home Theater Receiver Volume Problem .

    The fact you have to turn it backup is intriguing ... do you get full volume when turning it up? Or is it quieter than before? Maybe there's something causing it to trigger volume down, photos of the volume control with pcb? Check for any dirt and crap built up around the volume knob to where...
  7. C

    1.5v - 100V input.

    A 100v 400-600nf film capacitor will drop the voltage then rectify it via a diode, the other diode is there so the capacitor can discharge on each cycle... I'm not sure it's a great technique because if the cap fails, the base of the transistor will see 100v ... hence the optoisolator which...
  8. C

    1.5v - 100V input.

    For added safety an optoisolator could be used instead ....
  9. C

    1.5v - 100V input.

    I think everyone failed to notice "AC" You can use capacitor and it's reactance to lower the voltage to a safer level, i just designed this circuit..
  10. C

    LED strips not lighting up

    First confirm you have an out voltage... if it was the led strip, they tend to fade before death unless the copper strip cracked....
  11. C

    Battery charger with LM317

    The lm317 can be operated in 2 modes... Voltage regulation (voltage set from a resistor divider) Current regulation which limits the output to a set current
  12. C

    DC to AC 50hz 12vdc to 12vac

    It's a 12v water pump... and when i move it i'll take photos but right now the toroidal transformer works great!
  13. C

    DC to AC 50hz 12vdc to 12vac

    Ahhh ok a pure sine yeah easier to stick with the transformer :) thanks!
  14. C

    DC to AC 50hz 12vdc to 12vac

    Problem solved, found an old toroidal transformer! But still... im curious for a circuit
  15. C

    DC to AC 50hz 12vdc to 12vac

    I came across a water pump which requires AC, i only have DC not even an old transformer i could remove the bridge rectifier from... All the circuits i find invert and step up.. how fussy can a 2 wire 12vac 1.5w motor be?
  16. C

    Dimmer for 12volt AC LED strip

    PWM seems a good idea, better than heat loss via a resistor... A 555 could be an option for pwm?
  17. C

    Dimmer for 12volt AC LED strip

    AC 12v? They're usually DC, maybe a bridge rectifier on input...
  18. C

    Making a cap fed supply safe!

    It does not matter, nobody would be touching it anyway, it would simply be on or off in an isolated box away from people... the fuse should be fine as long as it blows (the tvs diode should blow it fast...)
  19. C

    Making a cap fed supply safe!

    The sim does not have tvs diodes or fuses! Lol But a fuse onto 240vac input side say 100ma or something and a tvs after the cap to ground ... When the cap fails the diode blows taking the fuse with it... should work (and i'm aware this is not driving a 1w, simple enough)
  20. C

    Making a cap fed supply safe!

    The point of the tvs diode is to clamp causing the fuse to blow, i know how they work and the dangers hence the question... Once the cap fails and 240v appears across the cap, the tvs diode will clamp blowing the fuse.... Maybe even a zener diode? Can't supply a circuit i've not yet built...
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