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  1. KrisBlueNZ

    About GPS data format?

    I think GPS receivers normally use the NMEA 0183 protocol. If that's what you're talking about, have a look at https://en.wikipedia.org/wiki/NMEA_0183
  2. KrisBlueNZ

    FM modulator light only and no transmitting

    Oh dear, that's not looking too healthy. You could start by cleaning the board by rubbing it firmly using cotton swabs dipped in solvent - isopropyl alcohol is best, but methylated spirit will do. Also, can you clean up the solder on the remaining transistor lead, so I can see what that pad does...
  3. KrisBlueNZ

    Relay Buzzing

    Yes, post several photos.
  4. KrisBlueNZ

    xor gate only use diodes

    How are you going to get your input states into it? Your circuit has two inputs. They need to be driven with logic levels - either high (1) or low (0). That's what the switches are for. If you have some other source of logic levels, you don't need switches. But to make that circuit usable, you...
  5. KrisBlueNZ

    xor gate only use diodes

    V2 is 0 because SW2 is switched to the downward position.
  6. KrisBlueNZ

    xor gate only use diodes

    Are you saying that in that circuit as shown, V1 and V2 are both 1, and Vout is 1? If that's what you mean, then that's wrong. V1 (from SW1) is 1 (high), but V2 (from SW2) is 0 (low) in that circuit as shown. Therefore the output SHOULD be 1 (LED illuminated).
  7. KrisBlueNZ

    Advice on USB-powered LED Lamp circuit

    Hi Andy and welcome to Electronics Point :) If that capacitor, C1, really is 1F (one farad), then yes, it will draw a surge current when you first plug the device into the USB socket, as it charges up. I doubt it will do any damage, but the problem is easily fixed by insering a 47Ω 1 watt...
  8. KrisBlueNZ

    Power supply circuitry not working

    Oh. Damn. I thought I was onto something there. OK, I'm pretty sure that the two end pins are the power supply from that board to the main board. On the main board, they connect to the electrolytic capacitor marked C1 that you can see in the last three pictures in post #6, and from there, they...
  9. KrisBlueNZ

    Power supply circuitry not working

    OK, I think this may be a lot simpler than I realised. Can you make some continuity measurements please. First I want to confirm that there's continuity between the points marked A and B, and continuity between the points marked C and D. Then check between B and C. If there's no continuity...
  10. KrisBlueNZ

    SN74HC595N Shift Register Problem

    Your SER, RCLK and SRCLK signals all need pulldowns. The pushbuttons and switches are only able to pull them up to VCC; when the switch or pushbutton is released, they will float. That's why you need a resistor from each of those inputs to 0V. You have the right idea with -SRCLK, where the...
  11. KrisBlueNZ

    FM modulator light only and no transmitting

    I'm not sure. According to post #7 you have about 5V between red and black. Is the polarity right? The red wire is positive relative to the black wire? If so, perhaps the regulator is working properly - perhaps the transistor was manufactured by a different company, and they used a reversed...
  12. KrisBlueNZ

    Need Some Help Figuring Out How to Use the PDSP2112

    Yes, you've figured out the overlap between the bit, byte and word variables. Your "Hello" code is loading bit patterns for the letters into w0 then calling the display subroutine, which accesses the bits individually as bit0, bit1, etc. You can shorten the display subroutine by using a loop...
  13. KrisBlueNZ

    Controlling Separate Source with Low Power Signal

    No problem. You can ask any questions about my circuit on this thread.
  14. KrisBlueNZ

    Stage Line 500W amp repair project

    Haha, that's great Pete! I would cover all of it, apart from the fusible resistor, in hot melt glue or similar, to give it some structural strength and prevent it from touching other parts. But you've got it, and you even replaced the bicolour LED with two red ones in anti-parallel. I thought...
  15. KrisBlueNZ

    FM modulator light only and no transmitting

    The circuit in the plug, using the KSE13003, looks like a standard emitter follower regulator with zener, but... the transistor seems to have been installed backwards! In other words it should be fitted so we can see its partly exposed metal face, not its plastic face with the part number...
  16. KrisBlueNZ

    xor gate only use diodes

    That's the right idea. If you want a real circuit that will work, you need to define the inputs, you need a current limiting resistor for the LED, and you should remove the earth at the LED's cathode.
  17. KrisBlueNZ

    Professional way to hide wires?

    Not sure if this is what you want, but... you can get a cool wire bundling system that consists of a plastic tube that has been helically cut, so you can unwind it and it wraps itself around your wires. If you fold back the excess wire between connection points, you can cover the wire with this...
  18. KrisBlueNZ

    PIC16F877A With GSM Modem SIM900A

    LOL! Well done Bob. I thought he said he could communicate with the modem from his PC using a USB RS-232 device. But he actually said that he could communicate from the PC to the PIC.
  19. KrisBlueNZ

    Members location

    Cool Ian :-) I don't suppose it's possible to put it on the same line as the location? Many posts are short, and adding a line in that section can add up to significant wasted screen real estate. Man I'm a picky bugger aren't I. I should just say thanks and shut up!
  20. KrisBlueNZ

    xor gate only use diodes

    Yes true Steve. The output cannot actually be a logic level; it's a voltage difference measured between the output points, and the bridge rectifier is just there to make sure that difference always has the same polarity. But we're not supposed to give away the solution so quickly!
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