Search results

Search Forums New Posts
  1. (*steve*)

    Capacitor charging

    What? that statement doesn't make sense. (how can you have discharge without charge???)
  2. (*steve*)

    Driving this MOSFET with PIC

    Well, if you require 2kV, those mosfets are simply not going to work. Unless you can tell us the nature of the load then we're really not going to be able to help you any further. And since you say it is similar in operation to a Taser, you're going to have to be very specific about what...
  3. (*steve*)

    Multimeter giving bad voltage readings

    As long as you know what ranges the meter works on, it still may be useful. There are times when two (or more) multimeters can be very handy. Compare readings with its replacement and document which ranges can be trusted.
  4. (*steve*)

    Capacitor charging

    Arcane R Us
  5. (*steve*)

    Help amplifying a tiny current

    Yes we probably should have warned you about the characteristics of SSR's
  6. (*steve*)

    Need help repair Sunshine ATX psu

    Do you have a circuit diagram for this PSU? There is at least the possibility that the PSU turns on but then immediately turns off due to overvoltage. Adding a load on the rails may help. The is also the possibility you're not jumpering the correct pins. Can you try it on another PSU...
  7. (*steve*)

    Driving this MOSFET with PIC

    I'm also curious about these 2kV transients. What are you switching? And how did you arrive at 2kV?
  8. (*steve*)

    Dr Who's K9 circuit help...

    They're are only 495 ways of selecting 4 from 12. This is completely doable from an eprom, and the number is actually large enough that of you ordered them randomly in the eprom you could go through them sequentially. However it would probably be less effort to do it with an Arduino. If the...
  9. (*steve*)

    Dr Who's K9 circuit help...

    Well, none are really complex, although they might sound like it to you. Using an arduino is probably the simplest in some respects, although if you need to drive a lot of LEDs you'll need to learn about charlieplexing. Another option is to build a number of LED flashers, each at a slightly...
  10. (*steve*)

    Driving this MOSFET with PIC

    That pic will run from 2V to 5.5V. If you are putting it from the 12V rail then I would go for a 5V regulator. It will allow you to switch the mosfet faster and turn it on harder.
  11. (*steve*)

    Dr Who's K9 circuit help...

    A shift register with appropriate feedback to generate a pseudo- random sequence, linked to the "buttons" in a random order could do the trick.
  12. (*steve*)

    Driving this MOSFET with PIC

    I searched for the voltage the pic was running out and missed the specification of the square wave peak voltage. Yeah operate it from at least 3.3V.
  13. (*steve*)

    Driving this MOSFET with PIC

    Yes
  14. (*steve*)

    Capacitor charging

    Ok if it was supplied with a 250V cap then that indicates the max voltage. Adding a higher voltage rated capacitor and expecting it to charge it to the higher voltage is a bit like placing higher speed rated tyres on your car and expecting it to go faster.
  15. (*steve*)

    Replaced Li battery in headset, but won't charge?

    The battery management may have failed. There is no really good reason to suspect there would be a visible short anywhere.
  16. (*steve*)

    Capacitor charging

    It could be lots of things. Do you have a circuit diagram? Do you have evidence that the inverter can produce voltages as high as 400V AND supply power at that point?
  17. (*steve*)

    Capacitor charging

    But there certainly may be a maximum voltage the inverter can generate.
  18. (*steve*)

    Capacitor charging

    Also, energy storage in a capacitor I'd proportional to the square of the voltage. When charging from a power supply capable of constant power (like a fly back inverter) the rate of charge will fall as the capacitor charges. If you have a voltage source and a resistor, the charging rate falls...
  19. (*steve*)

    Replaced Li battery in headset, but won't charge?

    Also... battery failure is rarely sudden. The chances are that the fault was not with the battery.
View older results
Top