Search results

Search Forums New Posts
  1. crutschow

    Charging cap with three phase

    What do you mean "not one is holding charge"?
  2. crutschow

    Diode Characteristic Graph

    Nothing much. The diode voltage vs current curve is rather independent of diode size at low currents, so you can't tell the diode size from that graph.
  3. crutschow

    TV/Projector ... the next generation?

    You need a darker room for a projector, of course, then for a flat-panel display which can be readily viewed with moderate room light. Depending upon the size you want, you are likely to find more bang-for-the-buck with a name-brand (Samsung, LG, Sony, etc.) 4k LED flat-panel. Even an older...
  4. crutschow

    How we can control the brightness of xenon light source

    Xenon lamps use a current-limited or constant-current source. Adding an adjustable limit to that source may do what you want.
  5. crutschow

    How we can control the brightness of xenon light source

    What type of xenon lamp?
  6. crutschow

    Sallen and Key Bandpass filter

    fo is the center frequency where the gain is nominally 0dB (1) for an op amp configured as a gain-of-one follower. You can do the filter with one op amp, as shown here.
  7. crutschow

    Op-Amp Gain

    I don't see which spec is for op amp A and which is for op amp B. :confused:
  8. crutschow

    Help using NPN transistors as a switch

    Then the transistor is incorrectly connected, or you have a faulty transistor.
  9. crutschow

    Receiverless sound system... how?

    A surround-sound setup is mainly for movies and is not really needed for music, since most music is recorded in stereo. So a two-channel stereo system should be adequate for your workshop (you can use more than two speakers to give music around the shop if it is large). Thus a Bluetooth receiver...
  10. crutschow

    VOLTAGE REDUCTION TO OPTIMISE STEP DOWN TRANSFORMER

    To elaborate on this, it can be done with a 220V to 10V transformer. The 220V primary side is connected to the 220V mains, and the 10V secondary side is connected in series with the 110V output with opposing polarity to reduce the total voltage (experiment to determine the correct polarity). The...
  11. crutschow

    PWM Controller Guidance

    Since the PWM is generated by an ATtiny13A micro, it's not possible to know what it is doing inside. Do you have an oscilloscope to look at the signal waveforms? As a shot in the dark, you could replace the ATtiny with a discrete PWM circuit. I have a typical circuit for that using an LM339...
  12. crutschow

    Anyone have any idea how I could fix the ~60ms transfer time of my UPS?

    The delay is likely due to the transfer time of the relay used to switch from the mains to the backup inverter. To avoid the transfer time you could use a UPS that operates off the inverter continuously, and just uses the mains to power the inverter and keep the back-up battery charged...
  13. crutschow

    Which transistor to switch power?

    Do you need to switch the high (power) side or can you switch the low (ground) side? What is the on/off signal control voltage from the micro? Will the two control signal lines from the micro both be low when the servo power is off?
  14. crutschow

    Op amp max frequency based upon slew rate and gain

    It ignores gain because the voltage in the slew-rate equation is the output voltage, not the input voltage.
  15. crutschow

    Op amp max frequency based upon slew rate and gain

    Yes, slew-rate is an intrinsic op-amp characteristic that is unaffected by frequency or gain. Do you know how to calculate the slew-rate for a sinusoidal signal, given its frequency and amplitude?
  16. crutschow

    shunt resistor

    How can we possibly help without a circuit diagram?
  17. crutschow

    Flyback + Cap charging time, help

    So it's quite clear you can't resist piling on the condescending, snarky comments, while misstating (or misunderstanding) what I said. And it's obvious your superior knowledge can't be improved (or you are a troll). So I'm not wasting any more of my time with you, since that's beating a dead...
  18. crutschow

    Flyback + Cap charging time, help

    That makes no sense to me. Core inductance is core inductance. No I'm not under that strange conviction and I don't believe in magic. .And lets eliminate the sarcastic, snarky comments, OK? I stated the energy stored in the core is due to the magnetizing current, which is different from the...
  19. crutschow

    Flyback + Cap charging time, help

    Okay, let's try again. A normal transformers core energy is the core inductance times 1/2 the magnetizing current squared. If you want to call that significant, that's fine, but that's not directly related to the much larger energy that can be transferred by the transformer from the primary to...
  20. crutschow

    Flyback + Cap charging time, help

    That is not true, but you are are condescending know it all, so I don't see why you posted here. o_O
Top