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  1. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    Are you trying to say that you can't tune the circuit?
  2. WHONOES

    AC Square Wave 10A Power Supply

    No. The PNP transistor at the bottom is schematically upside down. The 1K collector resistor of the same device should be connected to -15V as should the end of the 10K resistor that currently goes to ground. It would help future de-bugging if you could put indent's on each of the components in...
  3. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    Sorry, if you are referring to my circuit, yours bears little resemblance. If the filter is to reduce some of the harmonics, a tuned collector load will do the same without the complications of the unmatched filter you are trying to incorporate. I had a quick go and achieved -48dB for the second...
  4. WHONOES

    Is Kester 44 60/40 rosen core solder correct for general work?

    Yeah. I have recommended it on this forum before. A cheap source is undiluted windscreen wash which is pure IPA sometimes with a bit of surfactant in it.
  5. WHONOES

    PWM - Potentiometer ohm importance...

    Had a quick look at the one you bought, and its switching speed is 25KHz which is a bit fast. I run mine at between 50 and 300Hz. You might expect the motor to make a bit of a racket at that frequency but mine is OK but, having said that, mine are fairly low power 50 to100W or so. But I do get...
  6. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    Why do you need the filter?
  7. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    Sorry, I don't understand your last post.
  8. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    Putting your old circuit in post #95 is confusing.
  9. WHONOES

    PWM - Potentiometer ohm importance...

    It is difficult to tell fro the pictures in your link, but it is probably based on a 555 timer and if so the value of the pot is quite important. Using a smaller value would increase an already high switching speed. There also seems to be a lot of bits, which probably includes a voltage...
  10. WHONOES

    Unknown SOT23 - need help identifying

    Appearances can be deceiving.
  11. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    AS I explained somewhat earlier, the 100mΩ resistor in series with L1 is actually the dc resistance of the coil and is not an additional resistor. R4 is there purely for the simulator otherwise it thinks that L1 is a perfect inductor. This means that L! will then have an impossibly high Q which...
  12. WHONOES

    Lady bug robot

    I think this community might need a bit more information.
  13. WHONOES

    Motor peculiarity

    Worth a try.
  14. WHONOES

    Pedal powered generator

    Me too.
  15. WHONOES

    Hello, can somebody help wich transistor is like bfg520

    The "Sim" knows all it needs to about the Varactor diode. My version works fine. I think our protagonist is still trying to simulate, it's just that his terminology is a bit misleading / confusing. I agree with you comments about building on strip board. It can be made to work (I made versions...
  16. WHONOES

    Pedal powered generator

    I I like your style.
  17. WHONOES

    Motor peculiarity

    It's nowhere near as boring as watching paint dry. A simple re-wind only takes and hour or so.
  18. WHONOES

    Pedal powered generator

    What about an old fashioned dynamo that attached to the bike frame and just made contact with the tyre. I can just about remember the last time (getting on for 50 years ago) I rode a bike with one fitted and it certainly made a difference to the amount of effort required which may be enough for...
  19. WHONOES

    Motor peculiarity

    Spose you could always try re-winding it with a thicker wire if you feel so inclined! Have done so myself on a few motors and it doesn't take as long as you might imagine!!! Presumably it is just a 3pole type.
  20. WHONOES

    Unknown SOT23 - need help identifying

    Looks like a transistor of some sort. Had a quick google at what it might be. The T1s notation is shorthand in SMD speak and seems to be a BCX17 in a SOT23 package. See link to datasheet below. http://www.s-manuals.com/pdf/datasheet/b/c/bcx17%2C_bcx17r_zetex.pdf
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