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  1. KrisBlueNZ

    Ohms

    Hi there and welcome to Electronics Point :-) A transistor is a semiconductor, which is a class of components that (mostly) don't have resistance as such. They will give a reading if you measure them using a resistance range, but it may or may not be meaningful or useful. Also you should find...
  2. KrisBlueNZ

    Designing a Time Delayed Relay

    I recommend a 3-pin Phoenix MSTBVA connector, same as the others. Phoenix Contact do have some connectors with 0.15" (3.81 mm) pitch - see http://www.digikey.com/product-detail/en/1803439/277-1222-ND/260590 and http://www.digikey.com/product-detail/en/1803581/277-1162-ND/260530 - if you want to...
  3. KrisBlueNZ

    change components for flip flop circuit higher

    No worries. It depends on the frequency you want. Choose a frequency and calculate the cap using f = 0.72 / (RT CT) or CT = 0.72 / (f RT) LOL :-) Shall I PM you my address? LOL
  4. KrisBlueNZ

    Voltage Divider Questions

    Ah, you're right. I missed that. In post #4 as I mentioned. You need to remove the .txt extension - the forum software is fussy about filetypes.
  5. KrisBlueNZ

    Ordering PCB's help for my first design and order...

    Yeah, that looks like a good site! Thank Harald for finding it though.
  6. KrisBlueNZ

    change components for flip flop circuit higher

    Actually the BA6219 isn't very easy to use; I shouldn't have suggested it. Here's a circuit that uses the Infineon TLE5206-2, which is rated for 5A output current. U1 is a standard astable (oscillator) based on a 555. The frequency is determined by RT, which I've specified as a potentiometer...
  7. KrisBlueNZ

    Stage Line 500W amp repair project

    Two LEDs reverse-connected like that is fine. It's possible that the LED will flash ON for a moment at power-up while the circuit settles down with the right DC conditions.
  8. KrisBlueNZ

    Ordering PCB's help for my first design and order...

    https://www.electronicspoint.com/resources/pcb-prototype-manufacturing-calculator.23/
  9. KrisBlueNZ

    change components for flip flop circuit higher

    Well, I'll give you some vague suggestions then. Check out the following H-bridge ICs: http://www.digikey.com/product-detail/en/TA7291P(O)/TA7291PO-ND/1730026 (1A rated) http://www.digikey.com/product-detail/en/BA6219B/BA6219B-ND/658358...
  10. KrisBlueNZ

    Problem with Toshiba 26DV615DB LCD tv.

    Hi there Greg and welcome to Electronics Point :-) Sorry for the slow reply! I doubt I'll be able to give you any specific advice, but there may be other folks here who can. I found the service manual at http://elektrotanya.com/toshiba_19-22-26dv615d.zip/download.html. When you load the page...
  11. KrisBlueNZ

    change components for flip flop circuit higher

    OK, you have a toroid and you want to generate a magnetic field using one or two coils of wire so you can measure eddy currents. You want the injected magnetic field to alternate polarity at an adjustable frequency. You want the drive signal to be a bipolar square wave. Your best option would...
  12. KrisBlueNZ

    Unmodulated Carrier Recovery

    It might help us understand your question if you started by explaining the overall purpose of the project, as broadly as possible.
  13. KrisBlueNZ

    24V 2A Variable Power Supply

    So you're drawing 100 mA out of the regulator, which is set for an output voltage of 15V. What's the voltage on the collector of T2? T2 is being used in its linear mode. You can calculate the amount of power it will dissipate by multiplying the current flowing through it (0.1A) by the voltage...
  14. KrisBlueNZ

    Heatsinks for very hot Xbox Chips

    Does your console have a fan for forced air cooling?
  15. KrisBlueNZ

    Designing a Time Delayed Relay

    There's no clearances around the mains inputs - Phase and Neutral. Also, do you have a 0.1" connector for the mains input? If so, you can't! Personally, I would move the transformer north, put the mains connector south of it, and put most of the power supply circuitry "under" the transformer (on...
  16. KrisBlueNZ

    Heatsinks for very hot Xbox Chips

    Forced air (i.e. a fan blowing air through the heatsink fins) will make the biggest difference. If there's already a fan, you might try replacing it with one with higher airflow. Other changes won't make such a big difference. I don't have much experience; others will be able to help more.
  17. KrisBlueNZ

    Voltage Divider Questions

    ... No pun detected... I think you may want to use lower resistor values. You have the right ratio but the values are significant too. Except that you can't easily buy a 44k resistor. That's why I suggested that you reduce the ratio to a single number and use my Python program to suggest...
  18. KrisBlueNZ

    Stage Line 500W amp repair project

    OK good! Sorry for the slow reply. So the drivers aren't fitted? OK. Did you clean the heatsinks carefully? If not, do that. But leave the output transistors out. Then fit the drivers and clip them to the heatsink, then solder them. Then power up again. Assuming no fusible resistors go pop...
  19. KrisBlueNZ

    LED TV - power circuit damaged after lightning strike

    Thanks for posting the schematic in post #29. The circuit in post #26 is only a small part of the power supply circuit, and that MOSFET, Q603, is not the main switching MOSFET (Q601). I'm not sure what it's even there for; it seems to be connected as some kind of overvoltage detector, but its...
  20. KrisBlueNZ

    Voltage Divider Questions

    Hi Michael and welcome to Electronics Point :) Ignore Steve's post; I think he just read the question too quickly. This is the first time I've seen him get the wrong end of the stick and give an inappropriate answer. As Gryd3 said, the heavy current doesn't flow through those resistors. I...
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