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  1. KrisBlueNZ

    ? on wires to use for headphone repair

    Yeah, as I said in post 8. Any 3-conductor or 4-conductor wire with a stereo 3.5 mm jack plug on it will "work", but there are good reasons why headphone manufacturers use high-quality, highly flexible, high strength wire.
  2. KrisBlueNZ

    74HC138N: IC Beginnings Chapter Two

    That's great! That's exactly right. The reason this IC was designed with so many enable pins is to make it easier to use several of them together, to expand the number of inputs and outputs. A single 138 expands three binary inputs into eight one-at-a-time outputs, right? But say you want to...
  3. KrisBlueNZ

    Large array of 5mm LEDs (555 timer,LED flasher)

    OK, if the flash rate and the duty cycle are what you want, no problem. I was just checking that you were happy with them.
  4. KrisBlueNZ

    Bad output on DMX Splitter

    Hello again and welcome back :-) Can you post close-ups of just the faulty section, on both sides of the board. First please read carefully our guidelines on how to take useful photographs: https://www.electronicspoint.com/resources/how-to-take-photos-of-circuit-boards.6/
  5. KrisBlueNZ

    a more simple request (was solar / relay / timer control thread)

    What's the thing at the bottom, centre-right?
  6. KrisBlueNZ

    Is there any way to fix transistor voltage drop?

    Thanks Steve. I also have never used a PUT. I think I objected to the "Programmable" in the name. I thought, "A three-terminal device? That's not programmable! If that's your definition of programmable, you might as well call a transistor a 'programmable-gain transistor'!" And hevans1944...
  7. KrisBlueNZ

    ? on wires to use for headphone repair

    It depends what level of performance and reliability you want. I'm not talking about OFC or any other buzzwords, but there's a big difference in qualtiy between cheap ear bud cables and proper quality headphone cables. A lot of noise can be conducted into headphones when cables bump against...
  8. KrisBlueNZ

    Need Some Help Figuring Out How to Use the PDSP2112

    Right. I agree. Yes, good. It makes more sense to drive the -CS pin(s) from the shift register (or just tie it low if there's only one display) and drive -WR directly. That's what I wanted to avoid, because of the time taken to send three words to the shift registers. It will certainly be slow...
  9. KrisBlueNZ

    ? on wires to use for headphone repair

    Hi and welcome to Electronics Point :-) Headphone cable is not a commodity retail item. No doubt there is cable somewhere that's suitable for what you want, but you may have trouble finding it, especially in small quantities. I suggest you try specialist audio companies - start by Googling...
  10. KrisBlueNZ

    Designing a Time Delayed Relay

    Heatsinks are often made of aluminium, and/or anodised, so no, you don't solder them. Yes, I suppose you could use heat-conductive paste between the heatsink and the PCB, and you probably should use it between the transistor and the heatsink.
  11. KrisBlueNZ

    Need Some Help Figuring Out How to Use the PDSP2112

    Yeah, sorry, -CE. Chip Enable, Chip Select, whatever :-) And when there's no way to draw an overbar, I use a "-" prefix to indicate active low. There are other conventions - initial or trailing backslash, initial or trailing asterisk, "n" prefix, "-bar" suffix, ...
  12. KrisBlueNZ

    a more simple request (was solar / relay / timer control thread)

    Yeah. If he only wants to monitor one current flow, he could omit the second Allegro chip and feed a pot into the PIC input that was previously used for that Allegro chip. I'm afraid I'm not really clear on what he wants. Perhaps one of you guys will produce a block diagram at some stage to...
  13. KrisBlueNZ

    regulate 5v circuit from 4*AA batteries

    A buck switching regulator can't produce more output voltage than its input voltage, and they also have a dropout voltage. Some buck regulators that are designed to generate low-voltage supplies for processor cores have pretty low dropout voltages though. I guess it's the backlight on your LCD...
  14. KrisBlueNZ

    74HCT08: an IC beginning

    Great advice, but the 2N3906 is a PNP. Should be 2N3904.
  15. KrisBlueNZ

    Large array of 5mm LEDs (555 timer,LED flasher)

    1. The 15V 5W zener should be connected across the incoming supply, not in series with it. (Shown above.) 2. You had the incoming supply connected to pin 7 of the 555, not to the circuit's positive rail. (Shown above.) 3. You could reduce R6 to 10k, the same as R4. I recommend any value...
  16. KrisBlueNZ

    Need Some Help Figuring Out How to Use the PDSP2112

    Cool :-) Not sure if I made this clear or not, but you should drive at least one pin of the display from a directly controllable pin on the PIC. Probably the -CS signal. Then you set up the address, data, -WR, and any other signals you need, using the shift register chain, and pulse -CS low...
  17. KrisBlueNZ

    Identify part to replace help.

    Yes. Cool :-)
  18. KrisBlueNZ

    Identify part to replace help.

    luca120, I think you're right! I can see something that looks like LM3 on there. Also I noticed that pins 1~4 are all connected together, which confused me, but that's exactly what you'd expect if only one of the comparators was used. Yamye, ignore what I said about microcontrollers and...
  19. KrisBlueNZ

    Identify part to replace help.

    Hi there and welcome to Electronics Point :-) It's an IC (integrated circuit) but I can't identify it because the part number is unreadable - partly because the light is at the wrong angle, and partly because of the damage to the IC. If you can post a picture that shows the undamaged part of...
  20. KrisBlueNZ

    Need Some Help Figuring Out How to Use the PDSP2112

    The display needs at least 12 control signals. You may find it's cleaner to send the data using one or two shift registers, e.g. 74HC595s. These can be cascaded. The interface between the PICAXE and the shift registers is called SPI - serial peripheral interface - and is widely used. It requires...
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