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  1. GPG

    logging current over a 24 hour minimum period

    EG: http://www.yoctopuce.com/EN/products/usb-sensors/yocto-amp?gclid=CjwKEAjwh8exBRDyyqqH9pvf1ncSJAAu4OE3DGtFsfx019t-vPVUfeSTmjIhFbMQ5RRw2ldsd_lQgxoCjuTw_wcB What range? There are others.
  2. GPG

    Light Meter Problem

    The question is: do you need a light meter ? If so there are better ways.
  3. GPG

    ACS712 hall sensor

    AC or DC?
  4. GPG

    mosfet shorted after i connect them in parallel ? did i doing it wrong ?

    What BJ said. And http://www.microsemi.com/document-portal/doc_view/14693-eliminating-parasitic-oscillation-between-parallel-mosfets And your gate drive current is shared leading to higher switch times. The TL494 may be a bit lacking. What battery?
  5. GPG

    Logic family selection

    Which transistor? Perhaps you should show circuit. And why use (P)ecl? there are more options in other families.
  6. GPG

    Light Meter Problem

    The fact that the pot and IC got hot............
  7. GPG

    Light Meter Problem

    So many things wrong its hard to know where to start The pot wiper should be connected to -9 for starters
  8. GPG

    Logic family selection

    Choose a CMOS family. Put a large value resistor to ground from the floating input. Then I have to ask why?
  9. GPG

    reciever died, wont turn on

    .possibly fuse lighting up cant imagine its ash
  10. GPG

    Problem with IR2214

    These must be connected. You could try pulling them low to the appropriate point (the arrow in Fig4) but I would connect them to the drains via the recommended resistor/ diode Use a diode with the characteristics specified. Pg 13 /SY FLT and /FAULT SD must be separately pulled up. Monitoring...
  11. GPG

    Pitch to voltage conversion.

    http://www.ti.com/lit/ds/symlink/lm2907-n.pdf
  12. GPG

    How do I figure out these resistors?

    .Correcting error: Forcing beta to say 20 = Ib~12 mA Under worst case the 555 Vout will be ~ V+ -1,5 and Vbe = .6v so the voltage available to drive .12mA is~7V So 7V/ 12mA =~583Ω Nearest E12, 560Ω. https://www.fairchildsemi.com/datasheets/TI/TIP41C.pdf beta may be as low as 30 Using a logic...
  13. GPG

    Psychic amplification apparatus - calculating inductance??

    And the Drain/ collector capacitances
  14. GPG

    555 Timer Push-On, Push-Off but with timer as well

    Make R2 R3 1MΩ. As they affect the timing R1 may need adjusting.
  15. GPG

    transistor in saturation mode

    http://www.nxp.com/products/bipolar_transistors/low_vcesat_biss_transistors/
  16. GPG

    Adding hysteresis on a microcontroller

    Single rail. .The output of the (perfect) opamp can be Vdd or 0 The total difference is the hysteresis
  17. GPG

    How do I figure out these resistors?

    The 555 will pull down much better than up So the b-e resistor is immaterial. The resistor from pin3 should saturate the transistor. If you calculate it based on a low beta this will do. The idea is called forced beta http://whites.sdsmt.edu/classes/ee320/notes/320Lecture24.pdf In your case the...
  18. GPG

    Psychic amplification apparatus - calculating inductance??

    Yes but If you read the bullshit its an amplifier, the output is the same frequency as the "input":D And http://www.hamanuals.com/S1/CX7/Articles/Mosfet.pdf Ive been around longer than they have too.
  19. GPG

    555 Timer Push-On, Push-Off but with timer as well

    I think this will work It represents the first 555. Time between pushes is ~ 4 secs.Not tested or simmed. Edit All small signal diodes 1N4148. One of them may not be necessary
  20. GPG

    Help me...I'm trying to learn...

    What are the part nos of MF1,2
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