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  1. KrisBlueNZ

    Trying to repair a shaver charger

    OK, so it's a 1.2V 1500 mAh Ni-Cd cell. Recommended charging rate 450~500 mA for 5 hours. I can't find any suitable transformer to replace it but you would be better to use a little power supply module anyway. These are available with 3.3V output, which must be dropped down to 1.2V. This is...
  2. KrisBlueNZ

    Identify and Source damaged component?

    What Harald said. And the 'K' after the voltage probably means ±10% tolerance. This value is available in several different sizes. Measure the one you have there, then match it to one of the options in this selection guide on the Digi-Key web site...
  3. KrisBlueNZ

    External Monitor Project...need help

    It could be faulty, but it could also be that your HDMI signal isn't compatible with it. When you connect a computer's HDMI port to a display, the display tells the computer what resolutions, colour depths, and scan frequencies it supports, and the computer chooses the best one that it is able...
  4. KrisBlueNZ

    Counter kit Shortcut??

    Hi Shane and welcome to Electronics Point :) The simple answer is that it depends on how much voltage the larger segments need, and what current (brightness) you want to run them at. From your description ("decent size scoreboard") I think the answer is probably no. In that circuit, the LED...
  5. KrisBlueNZ

    External Monitor Project...need help

    Did you read this sentence in my previous post? Can you find or borrow something that does have those outputs? The Menu button needs to work even if there is no signal on the currently selected input, otherwise there's no way to change to a different input! So you should try to find out why...
  6. KrisBlueNZ

    External Monitor Project...need help

    Hi there and welcome to Electronics Point :-) That looks like a pretty nice controller board there. So I assume the "NO SIGNAL" message is displayed on the LCD panel itself. That means that almost everything is working. Just the controller board thinks it's not getting any signal. Have you...
  7. KrisBlueNZ

    Trying to repair a shaver charger

    Also, can you post any technical information you have on the shaver, and the instructions for charging. Is the battery removable? Can you find out anything about it?
  8. KrisBlueNZ

    Trying to repair a shaver charger

    Yes, keep going. It doesn't matter if you break the wire since you won't be able to repair it. Were you not able to prise the iron core apart?
  9. KrisBlueNZ

    Replacing a Photoresistor with Triac question

    I've seen the arrangement he describes before - the LED is driven at constant brightness, and an angled "blade" attached to the pedal is used to vary the amount of light that falls on the photodetector, to vary the speed. If the controller is non-isolated, that should be clear from photos of...
  10. KrisBlueNZ

    Trying to repair a shaver charger

    Right, that's good. The primary winding is the blue wires. It reads open circuit. That's the normal way that a transformer will fail if you plug it into twice the rated voltage. See how far you can dismantle the transformer. If you can remove the tape around the windings, do that first...
  11. KrisBlueNZ

    Stage Line 500W amp repair project

    OK, R177 is in a different part of the circuit. If Q46 collector is still 0V there is still the same problem with that part of the circuit. Have a close look around R108. There's something strange going on there. What's the +45VL voltage that Adam asked for?
  12. KrisBlueNZ

    Stage Line 500W amp repair project

    It does seem like quite a lot, doesn't it. I think it could be normal though. Yes. There's 82V across R117 which means there is 3 mA flowing in that circuit. That should cause 3V drop across R108 with Q4 removed. Do you mean R117? OK, cool! (Literally.) What is the voltage at Q46 collector?
  13. KrisBlueNZ

    Trying to repair a shaver charger

    Hi Peter and welcome to Electronics Point :-) I agree that it seems to be a combined transformer/rectifier, according to the specifications (1.2V DC output). It's possible that the shaver is damaged, but I think that's unlikely. The resistance of the primary will be more than a few ohms...
  14. KrisBlueNZ

    Can you use serial communications on ethernet?

    OK, so it transmits information when events occur. You could try capturing that data through the serial port in a PC or other device. If you have an oscilloscope you can look at the data stream and figure out the bit rate, otherwise you'll have to try them all one at a time. You may find that...
  15. KrisBlueNZ

    How can µF-range capacitors reduce AC voltage?

    duke37 is pointing out two disadvantages of having C1 present. The four LEDs in series clamp the votage across C1 to about 12V (depending on the LED type). If the LED path goes open circuit (a failure of any LED or a break anywhere in that path), C1 will try to charge up to about 310~320V DC...
  16. KrisBlueNZ

    Heathkit IP20 Power Supply

    OK, cool! So you'll need to install a new R18. BTW please don't call me "sir" :-) Those voltages also show that about 10V is being dropped between B and C. This points to a problem with the current range switch, specifically the "CR-2" wafer, shown to the left of X1 on the schematic diagram...
  17. KrisBlueNZ

    Python programming course help

    LOL YW
  18. KrisBlueNZ

    Python programming course help

    Oh sorry! I didn't think that "Gregarious Giraffe" would be you! I assumed it was either a bot or someone the site assigned to help me. No problem :-) I like that site as well.
  19. KrisBlueNZ

    Python programming course help

    I'm not sure what you mean. It seems to behave the way I expected. When it gets to line 4 and s="n" it will call itself one more time with s="". That could be avoided by checking for len(s) > 1 before calling prend() again, but that duplicates the check that already has to be made in line 2 to...
  20. KrisBlueNZ

    Python programming course help

    In computer science, recursion has a specific meaning. It doesn't just mean to happen repeatedly, or to drill down recursively into subdirectories. It refers to a function that calls itself, either indirectly, or more commonly, directly. Look at a typical program. def print_string(s): for...
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