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  1. KrisBlueNZ

    Yamaha RX-V459 receiver/amplifier does not power on

    You can get a version of the service manual from elektrotanya at http://elektrotanya.com/yamaha_dsp-ax459_htr-5935_htr-5940_rx-v459.pdf/download.html. There are several speaker relays, and they are all controlled by the microcontroller in the DSP section. There could be a number of reasons why...
  2. KrisBlueNZ

    Chicken Coop Door Opener

    No worries. I understand! That schematic looks great. Nice work Dan :-)
  3. KrisBlueNZ

    No Color. Black and White Picture

    I have never heard of this happening. You may be thinking about heater to cathode shorts that can occur and can sometimes be cleared by applying a large current pulse. Have a look in the neck of a CRT sometime and you'll see that the control grids and accelerating anodes are too far apart to...
  4. KrisBlueNZ

    No Color. Black and White Picture

    I'm afraid that's absolute rubbish. Please stick to advising people on subjects that you have some knowledge and experience with. The colours in a CRT are controlled by the cathode voltages, not the control grid voltages. In any case if you read post #4 you will see that this explanation can't...
  5. KrisBlueNZ

    Meg ohm resistors , are opens circuits?

    Davewalker5, have you heard the story of the blind men trying to describe an elephant, but each one touches a different part, and they all get different ideas of what an elephant is like? I feel a bit like one of those men. You have asked a lot of questions about different parts of the same...
  6. KrisBlueNZ

    Chicken Coop Door Opener

    Either of those is fine. No need to keep thanking me!
  7. KrisBlueNZ

    Dynex DX-L42-10A Intermittent Issues

    Yes you could try a few things. You could replace C513 (2.2 µF) on suspicion. I don't think it's likely to be a problem but it's an easy change. Check D503 and D506 with one lead lifted out of circuit. Set the multimeter to the highest resistance range and connect the red lead to the cathode...
  8. KrisBlueNZ

    does this seem right?

    Right, OK. Assuming the controller drives a motor with PWM, you can convert the two motor control signals to a direction and an enable signal using a bit of logic. Here is the translation you need: MOTORA MOTORB DIRECTION ENABLE L L any OFF L H...
  9. KrisBlueNZ

    Questions on power supply

    Fish... I wouldn't bother arguing with Colin. No good will come from it :-/ Just...
  10. KrisBlueNZ

    Help in designing a timer circuit

    Yes, you can use a 555 as a monostable to produce a pulse of about 45 seconds. Start at http://www.google.com/search?q=555+monostable and feel free to ask any specific questions here.
  11. KrisBlueNZ

    No Color. Black and White Picture

    OK, well I'm out of suggestions :-(
  12. KrisBlueNZ

    Chicken Coop Door Opener

    The secondary fuse should be 600 mA or a bit more. You already have that - F2 is 600 mA. You could move it to before the bridge rectifier though, so it will blow if the bridge rectifier fails. F3 in the primary side can have a lot lower current rating. It might be wise to use one rated for at...
  13. KrisBlueNZ

    does this seem right?

    Ah, I see. In that case you need a bit of logic to convert the two motor control outputs to a direction and an enable. It would be interesting to know whether the +2.5V he measures on each motor control wire is DC or a PWM signal. OP, do you have an oscilloscope? Can you look at the signals on...
  14. KrisBlueNZ

    does this seem right?

    According to the page at http://www.servodatabase.com/servo/towerpro/mg995 that has a motor built in. And I guess the connections to it would be power and control inputs. Not outputs that you can use to control an external H-bridge. What am I missing? I don't know what you mean.
  15. KrisBlueNZ

    Help in designing a timer circuit

    Hi there and welcome to Electronics Point. This sounds like an application for a microcontroller. You could try defining your requirements clearly and post a job offer on http://www.freelancer.com.
  16. KrisBlueNZ

    ICSP for PIC microcontroller using USB

    Using a device programmer such as the Microchip PICkit 2 or PICkit 3. There are third party replacements but people seem to have trouble with them. Actually, the PICkit 3 isn't exactly reliable either!
  17. KrisBlueNZ

    Hello!

    Dave: Snap!
  18. KrisBlueNZ

    Hello!

    Hi Adais and welcome to Electronics Point :-) What are your interests in electronics?
  19. KrisBlueNZ

    need help identifing this diode,radar unit

    <shrug> People sometimes think strange things :-)
  20. KrisBlueNZ

    2 stage op amp question

    I don't know what considerations become important at higher voltages - apart from the breakdown voltage ratings of the components, of course! Yes, more stages are needed if you need more gain, and that does make it more difficult to stabilise because it reduces the phase margin. But that's as...
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