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  1. Arouse1973

    Counter

    You want an event counter. Something like this might work http://docs-europe.electrocomponents.com/webdocs/1151/0900766b81151eec.pdf Adam
  2. Arouse1973

    Lost amateur :)

    Sorry not a chance with those dimensions. 6mm thick, say -3mm for plastic case thickness leaves 3mm. 1.6mm for standard PCB leaves 1.4mm for components, battery and sounder. I think you need to re-consider your sizes. Cheers Adam
  3. Arouse1973

    Lost amateur :)

    So you set this thing of before you leave the woods then. What time duration between beeps would you need? What size constraints do you have if any? You could run it from a lithium primary cell like the LS17500.
  4. Arouse1973

    Brushless Motor Help:

    I don't know of a way unless you run it in Liquid Nitrogen. Adam
  5. Arouse1973

    120v AC to multiple 12v DC?

    You need a power adaptor. What current are you expecting the circuits to draw? Adam
  6. Arouse1973

    Lost amateur :)

    This isn't for trapping animals is it? What do you loose in the woods? When you say clicker what do you mean? Adam
  7. Arouse1973

    Cut off system with two momentary switches

    Something like this might work. Adam
  8. Arouse1973

    battery charger

    I thought it was 12Vrms output of the secondary, now it's 24V? Which is it? Adam
  9. Arouse1973

    impedance of a constant current source

    Can you supply a diagram of both options. Adam
  10. Arouse1973

    Capacitors and Leds

    Here you go. You need to choose a logic level FET and depending on the super capacitors used set the balancing resistors R5 and R4 to 50 times the leakage current. Choose R1 for your current, see if you can work it out. Just remember that if you are using a higher supply voltage then add...
  11. Arouse1973

    Capacitors and Leds

    For some reason I have 20 seconds in my head? Dukes right but I made my calcs on two 3V caps in series. Adam
  12. Arouse1973

    Inverter That Produces a Sine Wave

    This sound interesting. When you say using PWM what does changing the pulse width do in your circuit? Do you have a circuit we can look at? Thanks Adam
  13. Arouse1973

    Brushless Motor Help:

    Why would you want to do this? Adam
  14. Arouse1973

    battery charger

    Charge with a constant current of 250mA for 14-Hours. Don't worry a bout the output voltage the battery will take care of that, just have at least 18V on the input. As mentioned above if you want to do it properly then two more stages are needed topping charge which reduces the constant...
  15. Arouse1973

    Capacitors and Leds

    The capacitor would need to power the constant current source and will just roll off at some point as the capacitor discharges. The LM317 will have a voltage drop across it and will limit the amount of energy you can take from the capacitor even with a 6 volt cap. You will need a different kind...
  16. Arouse1973

    12V Battery Charger Schematic

    The 500R can be replaced by a diode reversed biased. It is used to discharge the circuit when power is removed. The diode is used to turn the transistor and LED on when the output is low indicating charging in progress I guess. If it was not there then it would interfere with the circuit...
  17. Arouse1973

    Capacitors and Leds

    Your going to need a large 0.5F 6V capacitor and as Duke says a constant current discharge down to 3V at 70mA to give you about 20 Seconds. You are also going to have to wait a fair while for this to charge back up again before you can re-use it. Adam
  18. Arouse1973

    BJT Lab help(2)

    Don't assume 0.7V Vbe, it will be less than that. It's about 6V with such small collector current. Vbe will be 0.7V at about 6mA IC. So your base current is about 2uA. The current is not the same in the collector as the emitter. This is where your figures are incorrect. You need to know the gain...
  19. Arouse1973

    servo motor with windshield wiper engine

    So the size is what about 1/5 scale? Then you need a hefty servo. We used to use something like this. http://www.mattysmodels.info/Steering_Servo_18kg_For_Yama_buggy_15_scale_part_no_81801/p989433_5309211.aspx Adam
  20. Arouse1973

    Another Bat Detector

    Because of the low impedance on the output, when you drive it with a square wave the only part that you will see is the fast rising edge of the pulse and when this stops, the inductor will quickly pull the out put to 0V and as the magnetic field collapses you will have a fly back voltage that...
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