Search results

Search Forums New Posts
  1. KrisBlueNZ

    Application of 7805

    Is that all you want to do? You want a 5V supply that can provide more than 1A current? That circuit won't do that; all it does is feed current into the base of the transistor, which makes the transistor conduct, but nothing more. You need to look at an earlier post on this thread by CDRIVE...
  2. KrisBlueNZ

    Frequency Multiplier

    Harald, this is a PWM signal and he (presumably) wants to retain the same duty cycle at the output. A PLL isn't what's needed here. But I don't think it's worth responding until he posts a lot more detail about what he wants to do.
  3. KrisBlueNZ

    Frequency Multiplier

    You could do this with a microcontroller. You'd need one with timer input capture and a PWM generator (or something extremely quick, if you wanted to do it all in firmware). Another approach would be to convert the incoming PWM signal into a proportional voltage, and generate a new PWM signal...
  4. KrisBlueNZ

    Young jedi needs pcb/switch type assistance!

    Is it a good idea to switch the high-voltage path? You could switch the battery between the four inverter boards instead. That would mean four PCBs instead of just one, but might be safer and more reliable. Just asking.
  5. KrisBlueNZ

    Boost solenoid driver circuit

    Cool! Good job.
  6. KrisBlueNZ

    Tucker

    If you want to see a really strange Aussie movie, check out Bad Boy Bubby. It's euphemistically referred to as a "cult" movie. The first half-hour is set in a squalid bed-sit and is quite disturbing and not for the faint of heart, but the rest is very funny and very touching. I personally love...
  7. KrisBlueNZ

    Tucker

    Thanks Dave. He enjoyed it too. I hope it doesn't offend anyone with that surname. It's all meant in good humour.
  8. KrisBlueNZ

    Tucker

    Speaking of "tucker" reminded me of this little story I put together for an Aussie by the name of Jim Tucker. I thought you might get a laugh out of it. No offence is intended to anyone with that surname, or Australians in general. Please take it in good humour. WARNING: ADULT THEMES! From...
  9. KrisBlueNZ

    The newbie's secret circuits circus

    CDRIVE, nice work! It has all the important elements: a rotating disc, magnets and coils, and diodes. Diodes are very important, you know. It could do with a few capacitors though. Maybe some of those super-low-inductance ones. So, are you going to start your own "over-unity" web site now? LOL
  10. KrisBlueNZ

    Is this mosfet good for my project?

    As Steve said, you need to clarify this "T1" business. You have two points marked "T1" in your schematic. Normally this would mean they're connected together. If not, you should draw how they are connected. You also need to draw the fuse, and the igniter. Draw the whole thing so we can see how...
  11. KrisBlueNZ

    The newbie's secret circuits circus

    Thinking more along the same lines, here's a suggestion that might be less disruptive. A user (the OP) starts a thread by asking a question. Any user can read the thread. If he thinks that the OP should provide some other important information, instead of posting a reply, he can click...
  12. KrisBlueNZ

    The newbie's secret circuits circus

    I'm not surprised. Perhaps... and this is only a perhaps... the forums could be changed so that moderators and/or experienced users could flag a particular thread for "more information needed", and it would be temporarily blocked from accepting responses from other users until a moderator or...
  13. KrisBlueNZ

    The newbie's secret circuits circus

    It often seems like that to me too. I try to give them the benefit of the doubt and assume there are other reasons. I think it's partly because people (males, especially) like to think that they should be able to figure things out by themselves. Asking for help is seen as weakness, and they...
  14. KrisBlueNZ

    Application of 7805

    (*steve*) and duke37 have already tried to explain this. You have a transistor with its emitter grounded, and you want to feed about 1A into the base, from a positive power source. Is that right? All you need is a resistor between the positive power source and the base. When the transistor is...
  15. KrisBlueNZ

    Need help getting LCD panel to work

    Yes, that'll be fine. Maybe. Those two inputs on the backlight board should be driven by something, not just left floating. I don't know whether they're both analogue, both digital, or one of each. I suspect at least one will be analogue, so you can control the brightness. If the Raspberry Pi...
  16. KrisBlueNZ

    Pink noise generator circuit mod

    Corrected schematic with a small change to the way the SWM circuit drives the latch - now the connection is through the +ON signal only, using two diodes. When the manual switch is turned ON, ULC output goes high and a positive pulse (transition from GND to VCC and back) is coupled into +ON...
  17. KrisBlueNZ

    Pink noise generator circuit mod

    Here's an updated schematic with the RF Solutions receiver and some other small additions. There's a lot of extra circuitry to deal with the signals from the manual switch (SWM) and the receiver, but it's really just one IC and a whole lot of resistors and capacitors. Here's a description for...
  18. KrisBlueNZ

    Boost solenoid driver circuit

    I don't think there's any rotation involved. It's just a solenoid - an electromagnet that moves some component between two positions, to direct air from a "common" port to either the "normally open" or "normally closed" port. I think it responds directly to the drive frequency, so the duty...
  19. KrisBlueNZ

    Pink noise generator circuit mod

    For testing, you can wire the circuit to a jack plug and plug it into the jack socket on one speaker. Once you mount the circuit inside a speaker, it will be soldered to the jack socket inside the speaker, and you can use a jack-to-jack cable from that jack to the jack socket on the second...
  20. KrisBlueNZ

    Pink noise generator circuit mod

    Right. I don't think it will be a problem having the circuit running all the time. Sure, you can daisy-chain one speaker off the other. The input connector will double as an output connector when the noise generator is enabled. Does the amp have an unbalanced input? In other words, a jack...
Top