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  1. KrisBlueNZ

    Nand Gate oscillator help

    This circuit uses two gates as a set-reset latch and will do what you want.
  2. KrisBlueNZ

    Nand Gate oscillator help

    You may have forgotten the diode between pin 11 and the components that follow. If you add it, the circuit will work the way you want - kind of.
  3. KrisBlueNZ

    Nand Gate oscillator help

    That circuit isn't going to do what you want. If the contacts drawn next to C1 are a touch switch, they won't do anything because that node in the circuit is driven by pin 11 of the IC. The behaviour you'll get is that when you touch the left hand contacts, the oscillator will run, and when you...
  4. KrisBlueNZ

    Need help building a basic digital counting circuit.

    Hi William and welcome to Electronics Point :-) One simple solution is the CD4026 (aka MC14026, HEF4026) decade counter with built-in seven segment decoder (see http://www.digikey.com/product-detail/en/CD4026BE/296-14260-5-ND/528411). You would need one of these for each digit, along with a...
  5. KrisBlueNZ

    Power supply circuitry not working

    Hi there JH and welcome to Electronics Point :-) Thanks for the thorough problem description and the annotated photos. It's great to see someone making an effort right from the start! It looks like the batteries are switched through the adapter socket. On your first picture, the top connection...
  6. KrisBlueNZ

    Controlling Separate Source with Low Power Signal

    Here's a circuit that should do what you want. It's a unity gain voltage follower with high-current output transistors (QP1, QP2). The 0~5V input voltage feeds into the non-inverting input (pin 3) of op-amp U1A. U1A will control its output in order to keep its inverting input (pin 2) at the...
  7. KrisBlueNZ

    Samsung TV power board help

    It could have been a factory mod I suppose. I doubt the capacitor would have broken, then moved and touched the jumper. I guess the capacitor could have exploded and taken out part of the jumper, but I would expect more damage to the PCB. It still seems mysterious to me. If you can't find...
  8. KrisBlueNZ

    Too many opportunities for spending....

  9. KrisBlueNZ

    Samsung TV power board help

    I can't really make out what's happened in that first picture, but I've never heard of jumper wires just vaporising in the middle like that one seems to have done. Usually, tracks will vaporise first. Is it possible that something has leaked onto the jumper and caused it to corrode in the...
  10. KrisBlueNZ

    Nand Gate oscillator help

    Not according to his description of what the circuit is supposed to do, in post #31.
  11. KrisBlueNZ

    Potentiometer help

    Hi there and welcome to Electronics Point :-) There is no typical or standard value for a squelch potentiometer; it depends on the circuit design. Remove it from the board and measure between the two end terminals. If it's not too badly damaged, that will tell you its resistance...
  12. KrisBlueNZ

    Blown Fuse = No Fuse?

    There is surely a reason why the fuse has blown in the first place. Without corrrecting that cause, the airbag control system is very probably not safe. We (the moderators) wish to warn you that a vehicle airbag system is a critical safety system and working on it yourself is risky. It may also...
  13. KrisBlueNZ

    Is a blown fuse the same as an absent fuse?

    A blown fuse is open circuit. If you remove the fuse from the fuseholder, or remove it from the board, nothing changes electrically.
  14. KrisBlueNZ

    LM2907 output saturates with i/p signal of 90% duty cycle

    Hi Chandan and welcome to Electronics Point :-) Please post your complete schematic and describe the input source in detail.
  15. KrisBlueNZ

    regulate 5v circuit from 4*AA batteries

    It's not a good idea to interrupt the supply to the IC. Better to connect the resistors in series with the stepper motor. If that means more than one resistor, each one will dissipate less power than the original single one, so you may be able to use smaller resistors. If not, you can still...
  16. KrisBlueNZ

    PC Speakers malfunction. Need help

    Yes, post some good clear pics, and tell us the model number. It's not likely we'll find any publically available service information, but it's worth a try.
  17. KrisBlueNZ

    Blown Fuse = No Fuse?

    Hi Riffdex and welcome to Electronics Point :-) Discussion of airbag systems probably falls into the "dangerous" category because of the injuries that can be caused if the system fails to deploy when it should, or deploys when it shouldn't. I have locked this thread until we (the moderators)...
  18. KrisBlueNZ

    Chinese Electronics Sales

    Are they still cheaper if you include the costs of having to deal with products that are of low quality, incorrectly or misleadingly specified, unreliable, or faulty?
  19. KrisBlueNZ

    Technical Management

    You are revealing your "pedigree", as well as your poor attitude. You also appear to be wasting our users' time. I suggest you adjust your attitude if you hope to continue here at Electronics Point.
  20. KrisBlueNZ

    Nand Gate oscillator help

    Those aren't schematics. The second picture in post #22 is a schematic.
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