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  1. GPG

    LM317 question.

    Recommended minimum load is 10mA. This is the current through the divider chain. So the top resistor is 120Ω The dissipation of this resistor will be ~ 120 x I² = 12μW. Repeat for the bottom resistor. so ¼W will be fine
  2. GPG

    help designing simple 4022 circuit

    Yes. And if you connect the leds directly to the outputs and the cathodes in parallel you will only need one current limiting resistor. http://www.vishay.com/leds/low-current/
  3. GPG

    help designing simple 4022 circuit

    Put a 5.1V zener to ground on the analogue output as a safety measure
  4. GPG

    Grid Tie Inverter MOSFET Replacement part IRFP25N50N

    What is the link DC voltage? You could verify the N/P question by checking the other FET Are they in parallel?
  5. GPG

    help designing simple 4022 circuit

    1.25V/120Ω ~= 10mA Not told what Vcc is but it would have to be ~ 10V 2mA leds are available.
  6. GPG

    help designing simple 4022 circuit

    What impedance is the control input?
  7. GPG

    oscillator help

    That bit is true, but there was much begatting before!
  8. GPG

    Drive two relays based on input voltage.

    Didn't want to step on any ones toes but.... Mulled a bit on drivers for the MOSFETS but figured its not a high frequency. Also tossed around the idea of using drivers instead of FETs And OP, recommend 10 turn sealed cermet trimmers for the adjustments, given the environment a coating (not on...
  9. GPG

    transistor pairing? or not?

    With all the cameras around? Gotta see this.
  10. GPG

    Drive two relays based on input voltage.

    Vishay have the dual mosfet. but any 20Vgs would be ok Not simmed
  11. GPG

    dirty waveform

    How about more info?
  12. GPG

    oscillator help

    "The transistor operates on a rising and falling CURRENT (increasing and decreasing current) into the base. That's why no-one has described it before" He's discovered the transistor!
  13. GPG

    help with simple picaxe problem and LED

    The trouble stems from the lack of information/characteristics for the 'puck'
  14. GPG

    Nitenol/Heat Pumps etc

    http://phys.org/news/2015-03-japan-space-scientists-wireless-energy.html https://www.google.co.nz/search?q=solar+power+stirling+engine+pdf&ie=utf-8&oe=utf-8&gws_rd=cr&ei=i9V8VuvkHoG0mwXQvoGICg#q=solar+power+stirling+engine+
  15. GPG

    Exactly what component is this?

    It could be .52Ω 2% The salmon colour used to mean high stability.
  16. GPG

    Touch sensor to activate light for set amount of time

    Looks just what you need from what understand of your requirements NPN out, Pullup to micro's supply. or programmable pullup (no problem with differing supplies, common ground) Dark on/light on, your call.
  17. GPG

    dirty waveform

    Could be 1/2 bridge with faulty low side drive.
  18. GPG

    Hello, can anyone recommend a heatsink for the LM338

    What are your input/output voltages? Do you need the 338 to be a current regulator? TO3 package?
  19. GPG

    Need help with long distance circuit

    Determine the resistance of the cable, the full loop.
  20. GPG

    About Servo Motors

    Standard input for RC servos is1mS to 2ms pulse 1.5 ms being centre. The spacing between pulses is not very critical. Not very complex at all https://en.wikipedia.org/wiki/Servo_control OP: you can make an oscillator from an op-amp and control the width of the pulse. That's your start. A big...
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