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  1. (*steve*)

    Components Buyers Guide [for Dummies]

    Futurlec is based in the Philippines, I think (or at least they regularly ship from there).
  2. (*steve*)

    why connect a jfet gate to source?

    OK, it does on my PC, but not on my phone.
  3. (*steve*)

    Modifying MOT to get 40KV

    How much work have you done previously with EHT voltages (in years)?
  4. (*steve*)

    Bench Power Supply?

    Do you have a specific need for this range of voltages and currents? If you can get away with (say) 0 to 30V at up to 3A for most of your work then the are many power supplies that may meet your needs. There are also some fairly reasonably priced 15A power supplies which may not have the same...
  5. (*steve*)

    why connect a jfet gate to source?

    Your link takes me to a menu of about a bazillion circuits. Which one is the one you're looking at?
  6. (*steve*)

    LED circuit Heat

    It sounds like you should be running your LEDs at 20mA. We have a resource describing how to use LEDs that you should look at. For higher current LEDs (which you may want to use in your application) you are better off with a constant current driver. The same resource has some simple circuits...
  7. (*steve*)

    Components Buyers Guide [for Dummies]

    Learning to read the datasheet should be your first priority. Post a link to the one you have and we can try to show you what to look for. In some cases you may need to look for an application note if this information has been split out of the datasheet.
  8. (*steve*)

    Why did connecting this resistor to Jfet gate make the circuit work?

    You shouldn't take the gate potential above the source. In your circuit there's nothing to do that. The 10M resistor limits the current through the forward based gate. It will still need things up, just by less.
  9. (*steve*)

    Transistor pair to switch between Voltages

    That's perfect. You weren't messing me around. I was posting on a phone and some words were autocorrected to other words which didn't make any sense. In addition it makes it really hard to draw pictures so I have to describe in words. You have done a great job! In your drawing, r1 and r2 can...
  10. (*steve*)

    Can I use 12 Ohms instead of 8 Ohms speaker?

    No. No. * Marginally. * Provided the speakers are each rated at about half the rated output power or more.
  11. (*steve*)

    Identify Triac from Varilight lighting dimmer switch

    The simple thing to do is to trace the power from the mains to the lamp. This will pretty directly go through 2 pins of the triac. The remaining pin will be connected to other stuff. If you can identify the pins and the package then you can see if the potential replacement triac (we're...
  12. (*steve*)

    More woes driving LEDs via PWM

    Because that's the threshold voltage. The current through the device at the threshold is defined as some small (and typically useless) value. Check the graphs of Ids vs Vds for varying values of Vgs. You probably want a couple of amps, and to do this without significant voltage drop across...
  13. (*steve*)

    Circuit Design

    How good is your understanding of the components you mention?
  14. (*steve*)

    Identify Triac from Varilight lighting dimmer switch

    A dimmer is unlikely to use anything other than a triac. That said, to confirm it, if the part number can't be confirmed, you need to trace out at least part of the circuit. Dimmers are generally pretty simple circuits.
  15. (*steve*)

    3mm 6v 30ma

    A "3mm 6V 30mA" what? Bulb, LED, connector, switch, or thronomister?
  16. (*steve*)

    transistor for open-drain / open-collector 25kHz PWM

    Since you don't trust me, I won't give you any more advice.
  17. (*steve*)

    Hasler Bern

    If you want 24VAC RMS sinusoidal, then you will need to boost your 24VDC to about 35V. There are various ways to do this, but it would possibly be easier to start with a higher voltage. Edit: I don't really know what you're doing. If it a model train controller? What current is required?
  18. (*steve*)

    transistor for open-drain / open-collector 25kHz PWM

    There will certainly be a problem if you put a pull up to a rail other than 5V. You can choose to believe me or not. Is there something you have against checking then fixing the gate drive? If so, you can just place a shottky diode between the microcontroller and the PWM input . So many...
  19. (*steve*)

    transistor for open-drain / open-collector 25kHz PWM

    The specs do not say you must use a pull down. They do give the voltage you need to pull the input down to, and they specify the max voltage at the input. Connecting the microcontroller to the input is within those specs. Also, I have told you what you most likely need to do to get the...
  20. (*steve*)

    transistor for open-drain / open-collector 25kHz PWM

    Great. You now have the correct solution.
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