Search results

Search Forums New Posts
  1. KrisBlueNZ

    running a 12v .5A fan from 24v 6.5A source

    Your power supply should have worked. The fan you have needs only 6W (power is equal to voltage multiplied by current; 12V × 0.5A = 6W). Assuming you don't have another 12V 0.5A fan to connect in series with the one you already have, you can try dropping the voltage using a resistor. The...
  2. KrisBlueNZ

    Multitasking an Arduino

    The main problem with proper multi-tasking on the small PICs (PIC10, PIC12 and PIC16) is that it's impossible to do a stack switch! Even cooperative multitasking can't be implemented properly. This is one of the biggest weaknesses in the small PIC architecture; even the AVR can be stack-switched...
  3. KrisBlueNZ

    Component suppliers

    USA Digikeyhttp://www.digikey.com/Wide variety of passives and semiconductors. Overseas shipping is expensive! Mouserhttp://www.mouser.com/Like Digikey but also tools etc Newark Element 14http://www.newark.com/- Allied Electronicshttp://www.alliedelec.com/US affiliate of rs-components...
  4. KrisBlueNZ

    Component suppliers

    KrisBlueNZ submitted a new resource: Component suppliers - Names and web addresses for companies that supply electronic components Read more about this resource...
  5. KrisBlueNZ

    Adding Aux input to older car stereo

    Yes; I'll make it a resource. It doesn't really belong in any particular forum. Edit: https://www.electronicspoint.com/resources/component-suppliers.34/ Input welcome. Moderators, feel free to edit. Others, PM me or post in the Discussion tab for the resource.
  6. KrisBlueNZ

    Boost converter 12V to 36V (25 mA load) using 555

    By magic :) Are you happy with the new title? BTW I was wondering about the efficiency of that circuit, because of the 2.2Ω series resistor, but it's actually about 85%, which is a lot better than I expected.
  7. KrisBlueNZ

    Boost converter 12V to 36V (25 mA load) using 555

    Thank you abuhafss. It's nice to be appreciated :-) And you're almost exactly right. I enjoyed experimenting with the design, and I did write up the explanation for the benefit of you and anyone else reading the thread, but it also benefitted me - I had to check my understanding and try some...
  8. KrisBlueNZ

    Adding Aux input to older car stereo

    Digikey and Mouser are the biggest, AFAIK. I couldn't say whether they're good or not, but here's the rest of my list: Fry’s Electronics http://www.frys.com/ More products than components Futurlec http://futurlec.com/ Also has PCB manufacturing and other services Newark Element 14...
  9. KrisBlueNZ

    New member from WV

    Hi and welcome :-) We hope you like it here.
  10. KrisBlueNZ

    Communication Protocols (Which one to use)

    Right. It's designed for use in electrically noisy environments as well. But you do need to make the protocol reliable - that may mean a message-oriented protocol with reserved values for start and end of message, and escaping for those characters when they appear in the data, and it will mean...
  11. KrisBlueNZ

    Communication Protocols (Which one to use)

    Not normally; in RS-485 systems that I know of, slaves only respond immediately after being addressed. Broadcast and multicast messages aren't acknowledged; slaves are polled one at a time after the broadcast/multicast to confirm that they received it, if confirmation is needed.
  12. KrisBlueNZ

    Communication Protocols (Which one to use)

    Thanks for the description of the project. Remember that there will be voltage drop in your power and ground rails, so one module's ground won't be the same as the next module's ground. The supply current can be minimised by using a high supply voltage and a switching converter on each module...
  13. KrisBlueNZ

    Help With Project

    For you and me, sure. To someone with no electronics or programming experience, which is 1ronman's situation, that comment is not helpful at all; it just makes you look like a show-off. Perhaps you would like to offer to design, program, and build this very easy project. How much would you charge?
  14. KrisBlueNZ

    Hi everyone

    Hi Steve and welcome to Electronics Point :-) We're glad to have you aboard. I'm sure your experience and clear explanatory style will be valuable here! Thanks for introducing yourself.
  15. KrisBlueNZ

    Multitasking an Arduino

    Good advice Steve, but there's probably little point posting on threads that are over a month old.
  16. KrisBlueNZ

    Help With Project

    This would need a microcontroller, which would need to be programmed. If your friend can't find an off-the-shelf product and wants a product developed from scratch, he would be looking at a significant development cost. If he can make do with something simpler, with a simple rotary control...
  17. KrisBlueNZ

    hair straightener pcb repair

    I'm afraid I can't find any technical information on the S9500. It's also potentially dangerous, being directly powered from the mains. It looks like they only cost around USD 40. Definitely not economical to repair.
  18. KrisBlueNZ

    Modifying Voltage Regulator Design !!!

    No. A junction transistor has a saturation voltage that's not zero, and poorly defined. This would mean that when you turn the transistor ON, the collector does not pull fully to 0V - it may sit at 50 mV, 100 mV, even 200 mV. The regulator output voltage won't be correct, and it won't be...
  19. KrisBlueNZ

    Boost converter 12V to 36V (25 mA load) using 555

    I've had a bit of a play with the 555-based design from post #18 in LTSpice. I don't like the fact that there's no monitoring of the current in L1. This is likely to lead to saturation, and loss of the magic smoke from the MOSFET. Also with the original design, the ON time of Q1 is too long...
  20. KrisBlueNZ

    Modifying Voltage Regulator Design !!!

    So you want to modify your circuit of post #1 to provide a software-switchable output voltage of either 1.2V or 1.0V? The simple way to do that is to add a second resistor in parallel with R47 which is enabled by a MOSFET. Unfortunately, turning that MOSFET ON will increase the output voltage...
Top