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  1. Arouse1973

    Finding out what frequency i am on

    Can you tell us more about your project and what it is. Do you have a circuit diagram? You can get variable inductors, they work by varying the position of the internal ferrite core. The capacitor value will depend on the inductor chosen and the LC ratio required. If you can give a bit more...
  2. Arouse1973

    IR2110 Mosfet Driver Capacitance Question

    Good point Kris. Adam
  3. Arouse1973

    Does anyone recognise this symbol?

    Interesting that sony uses RA for resistor array? Strange that the Ops circuit uses this for a single resistor. Adam
  4. Arouse1973

    Generic MCU banter (Choosing an MCU)

    What you have to remember is we dont always know the age of the persons asking the questions. I was a judge for the Lego contest for a local school for a couple of years and it gave the kids an introduction to software and electronics? I do agree that most projects would be better done with a...
  5. Arouse1973

    Strange interaction between LED array and LCD controller

    Well thats very strange I dont understand why adding extra components would make it work unless there was a timing issue in your code which is why it works with the LEDs. Adam
  6. Arouse1973

    IR2110 Mosfet Driver Capacitance Question

    Hi Fish I am not quite sure why you feel the need for extra capacitance for low frequency switching. You should always get high speed switching with this type of circuit, that's the whole point so it limits the time the MOSFET is in it's high ohmic region. The time between switch on and switch...
  7. Arouse1973

    Detecting a bullet for velocity calculation

    You basically want a fast metal detector. As the bullet passes by it will detune the metal detector by virtue of the induced eddy currents into the copper bullet. This is going to be small and very fast. I have designed a couple of metal detectors in the past and there are a couple of different...
  8. Arouse1973

    Strange interaction between LED array and LCD controller

    I agree with Steve, remove the LEDs from the LCD data lines. The data line should only go to the micro. Adam
  9. Arouse1973

    Does anyone recognise this symbol?

    The barreter has a oval circle and is not a fuse. I dont think we can make that assumption. It depends if you use IEEE or ANSI I guess. Thanks Adam
  10. Arouse1973

    Strange interaction between LED array and LCD controller

    Ok thanks
  11. Arouse1973

    Components help

    BAS16 diode I think. Adam
  12. Arouse1973

    Strange interaction between LED array and LCD controller

    Can you supply a circuit diagram please? Adam
  13. Arouse1973

    New LEDs from 0.8V !

    That looks good. Do you think they have a DC DC converter built in? They mention device current and not your normal forward current and voltage. Adam
  14. Arouse1973

    Variable voltage dropper for speed control of tattoo machine

    Yes emitter sorry. A PP3 battery has a very low resistance when new and could easily put out 5 Amps momentarily, It's less than the 0.5R I added. We are talking transients here not constant. Cheers Adam BTW it's 4:42am over there. Have you woken up or not gone to bed yet :)
  15. Arouse1973

    Simple Alarm Circuit help

    Could you not have both trigger the alarm when broken or open and then the owner switch off the alarm when he is there? Adam
  16. Arouse1973

    Variable voltage dropper for speed control of tattoo machine

    Here is the base current of a BCX38B with a 470uF cap on the emitter. A 0.5 R resistor from the supply simulating POT all the way up. It will be more than this if the POT goes lower. Cheers Adam
  17. Arouse1973

    Variable voltage dropper for speed control of tattoo machine

    Hi Kris As I said it might not be a problem. The transistor in question has a maximum base current of 0.2 A. When the circuit is first switched on in this scenario it's momentarily in common emitter mode, i.e. the base is very close to 0V or at 0V because of the cap and possibly the motors low...
  18. Arouse1973

    12v constant and 12v ignition together

    Ok that good. Cheers Adam
  19. Arouse1973

    12v constant and 12v ignition together

    But won't this power up your ignition? A word of warning, this thread might get banned if you don't connect the unit as per the manufactures instruction. Giving any advice which may effect the operation of a motor vehicle is not allowed on this Forum. I recommend you install it as it was...
  20. Arouse1973

    Variable voltage dropper for speed control of tattoo machine

    That looks good Kris. The base resistor I mentioned is for start up. Two factors I can see which may be ok. When the circuit is switched on with the 470uF discharged there will be approx. 1.2 Amps inrush through the base if the POT is set to zero. Also momentarily the motor will draw it's stall...
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