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  1. KrisBlueNZ

    Need help with a proof of concept prototype.

    OK, well, you'll get a lot more help if you take the initiative and investigate possibilities for every aspect of your project. I guess there's merit in the idea, and we will be happy to advise you on electronics-related specifics, but you have to be the driving force. Steve Jobs didn't achieve...
  2. KrisBlueNZ

    Vizio TV high pitched squealing noise from the back!!

    Squealing noises are often caused by loose windings or cores in power inductors or transformers and can be fixed by spraying the offending component with aerosol lacquer. If it happens while the set is OFF, it's probably in the standby power supply.
  3. KrisBlueNZ

    Need help with a proof of concept prototype.

    Hi there and welcome to Electronics Point :-) Have you worked out how to expel this jet of water? Do you have a pump in mind? What about the "sanitation light"? Do you have an example? How do you intend to power this unit? Battery or mains (line) power? I guess if it's to be used while...
  4. KrisBlueNZ

    Stage Line 500W amp repair project

    OK. I think it's best to replace the driver transistors as well. The original types are obsolete but Sanken make some pretty close equivalents. Here are the specifications for the original parts, from data sheets from SavantIC. This is mainly for my future reference. 2SD1763, 2SB1186 TO-220...
  5. KrisBlueNZ

    Interested in starting to learn to make LED signs (Basic Q's)

    Hi Chris M and welcome to Electronics Point :-) I like the look of that VOLT sign. There are several board options for the display boards. Many of them are described in a good article at http://www.robotroom.com/Breadboard-Hints-And-Tips2.html and shown at...
  6. KrisBlueNZ

    just signed up

    Hi and welcome to Electronics Point :-) We don't get many questions on toob gear, but I hope you find something interesting here!
  7. KrisBlueNZ

    Low voltage Relays

    It's hard to say because we really don't know what's inside the controller. Possibly as high as 4.7 kΩ. Not likely to be less than 1 kΩ. But it's really not critical. If the transistor is running at 2 mA base current instead of 1 mA, you're not wasting much power and nothing will be harmed.
  8. KrisBlueNZ

    Bose Wave Radio Model AWRC1G

    Hi there and welcome to Electronics Point :-) If you have the manual, you probably already know more than us.
  9. KrisBlueNZ

    Is this switch safe? Dual 26650

    You got it :-)
  10. KrisBlueNZ

    Low voltage Relays

    So you have a control signal that goes to +2V (relative to the 0V rail) and you want that voltage to turn on a transistor to activate a relay? A 133Ω base resistor is unnecessarily low and will waste a bit of current. This is what I suggest. Try a base resistor of around 1 kΩ. Measure the...
  11. KrisBlueNZ

    Use Capacitive Sensing to detect a train?

    How about using RFID tags? You would have to put an antenna coil under the "ground", and put an RFID transponder ("tag") in each locomotive. ICs are available to drive the antenna and receive the data from the tag. The IC that I've seen has a serial output that needs to be decoded by a...
  12. KrisBlueNZ

    Project Logs

    Cool. I was just wondering. And thinking we could get a double benefit from all your work.
  13. KrisBlueNZ

    Project Logs

    Cool. I was just wondering. And thinking we could get a double benefit from all your work.
  14. KrisBlueNZ

    Project Logs

    Do you think that there's a lot of similarity between resources and project logs? I think the resources could benefit from the new features you're adding. Resources and project logs should still be kept apart but they could be handled internally in the same way. What do you think?
  15. KrisBlueNZ

    Beginner circuit question - 555 timer

    Yes, but VF for any particular current (IF) is not tightly controlled. It varies from one batch of LEDs to another; it varies somewhat between LEDs in the same batch; it varies with temperature; it varies with age. The simple fact is that driving an LED with a fixed voltage is bad juju. It can...
  16. KrisBlueNZ

    Arghhh! I Hate RS232 :)

    Aww, that's OK. I said it was a group hug. You can join in as well ;-) BTW what's with using the KFC logo as your avatar? Are you trying to make us all hungry?
  17. KrisBlueNZ

    Arghhh! I Hate RS232 :)

    All good. I guess this must be the time to have the group hug, LOL :-)
  18. KrisBlueNZ

    Noobhelp: Variable resistor to switch - how to?

    Hello there Mr. panther backwards and welcome to Electronics Point :) As Steve says, comparators with a bit of hysteresis. What you want could probably be done with an LM339 (see http://www.digikey.com/product-detail/en/LM339N/LM339NFS-ND/458686) and a dozen or so small parts. It would be...
  19. KrisBlueNZ

    Wheel of FORTUNE HELP

    Your schematic is pretty short on information. What's the battery voltage? And every component should have a circuit reference so we can identify it when we're talking about it. Each of the four transistors drives a pair of LEDs in series, which have no current limiting resistor. As Colin says...
  20. KrisBlueNZ

    Stage Line 500W amp repair project

    I'm not really sure how far back to go into the circuit with checking semiconductors. Let's start with the driver components, which are the four transistors that are clipped to the sides of the heatsinks, and several other smaller components in that area. Here is a complete list...
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