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  1. KrisBlueNZ

    Art Project Help (Complete beginner)

    I've deleted the second thread. There were no replies on it. Gryd3 has answered your questions very well. I assume you want the whole sequence, covering both lights, to be coordinated to some extent, and controlled from the same logic? You just want it to APPEAR as though one end is receiving...
  2. KrisBlueNZ

    stereo capacitors

    Your questions are already answered on this thread; that's why I didn't reply to post #19. 1. Regarding the resistance of the primary of the mains transformer. In post #11 you said you measured 0.00 with the meter set on 2000k. That's the wrong range; in post #12 I said that you should use the...
  3. KrisBlueNZ

    5v spike using DC-DC LM2596T-12/NOPB, Switching Regulator

    An analogue meter won't give you a misleading indication when the voltage changes quickly, assuming the meter movement is properly damped. An auto-ranging digital meter could be misleading. Try setting your auto-ranging meter to manual range hold. How many conversions per second does it make...
  4. KrisBlueNZ

    Detaining max load capacitance before pulse transitions are distorted

    I must be missing something. ANY amount of load capacitance will distort the signal somewhat. Also they probably need to specify the shape of the edges. Or do you assume they're straight? How do they define "distorted"?
  5. KrisBlueNZ

    LED TV - power circuit damaged after lightning strike

    Ah yes, thanks Dave. The bridge rectifier is the best place to start.
  6. KrisBlueNZ

    LED TV - power circuit damaged after lightning strike

    Assuming it's a switching power supply, which it almost certainly is, the usual problem is destruction of the switching device (usually a MOSFET) that drives the primary of the transformer, due to overvoltage from the surge. Other semiconductors on the primary side, and possibly also the...
  7. KrisBlueNZ

    5v spike using DC-DC LM2596T-12/NOPB, Switching Regulator

    A digital multimeter? Auto-ranging or manual ranging? Can you find or borrow an analogue (pointer-type) meter?
  8. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    With those values the 555 will oscillate at around 60 kHz with a duty cycle of around 60%. This corresponds to a MOSFET ON time of about 10 µs and an OFF time of about 7 µs. That MOSFET is rated for 75V VDS, 11 mΩ RDS(on), 76 nC gate charge and 5 nF gate capacitance. "Pretty warm" is probably...
  9. KrisBlueNZ

    5v spike using DC-DC LM2596T-12/NOPB, Switching Regulator

    Hi there and welcome to Electronics Point :-) Are you sure this surge is really present across the output? How are you detecting it? If you're using an oscilloscope across the output, try connecting the tip of the probe to the earth point in the circuit and powering it up. If you see a large...
  10. KrisBlueNZ

    KLH R3000 Stereo Receiver wont turn on.

    It's a supercapacitor. 0.047 farads, 5.5V, polarity as marked. Here's a suitable replacement: http://www.digikey.com/product-detail/en/DX-5R5V473U/604-1029-ND/970190
  11. KrisBlueNZ

    what is this Circuit ?

    Just wondering... why did you start this thread? If someone had told you exactly what that circuit did, how would that help you?
  12. KrisBlueNZ

    PLL (CD4046) FOR 50Hz

    Post the design of your LM358-based zero crossing detector. How much jitter were you getting with that circuit? What did the output of that circuit feed into, for phase angle measurement? Were you using a microcontroller? Are you using the AC mains as the sinewave source for your tan delta...
  13. KrisBlueNZ

    Is this possible ??

    Hi Eddie. Could you clarify a few points. Does the motor speed need to be variable at all? Are the "forward" and "reverse" pushbuttons momentary controls that operate the motor at full speed regardless of the Hall sensor and the Flexiforce sensors? Do you want the controller to always run the...
  14. KrisBlueNZ

    what is this Circuit ?

    The pole frequency for the op-amp part may be at 2 kHz but what about the input pole formed by the 157k resistor and the 22 µF capacitor?!
  15. KrisBlueNZ

    Slow day at the Forums...

    It's a conspir... I mean, I think it's just a combination of random factors.
  16. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    OK, that's a Darlington transistor, not a MOSFET. But you used a MOSFET? What type number? And you used a 100Ω resistor instead of the 10k resistor in the drive signal? Some information on the transformer core would be good too! Or at least an inductance figure.
  17. KrisBlueNZ

    what is this Circuit ?

    LOL :-) I really don't know. I think either it was drawn wrong in the first place, or it has a deeper function. BTW I think C1 is 5 nF. But don't worry about it! I think we've already spent far more time on this thread than it deserves, given the OP's flippant attitude.
  18. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    I don't remember seeing any circuit that uses a 555 and a transformer. AFAIK the only circuits using a 555 were in the other thread, and they used an inductor.
  19. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    To keep the inductor's physical size reasonable, you need to run the converter at a much higher frequency. The 555 is not good at that. Its output is not really strong enough to drive a big MOSFET quickly and cleanly either. The circuit wastes significant voltage (0.7V) in the current shunt...
  20. KrisBlueNZ

    what is this Circuit ?

    Adam, none of your circuit references match the original and C1 is not present in your redrawn diagram. I think the circuit could be something more complicated than a voltage reference but I won't speculate without proper information from the OP.
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