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  1. hevans1944

    Hooking up deadbolt motor to TB6612FNG Stepper Motor Controller

    I will have to defer to @Minder's experience and expertise, which is considerably greater than mine. I wasn't aware that a PM DC motor behaved like a DC motor with a shunt-connected field, but it does make sense because the magnetic field is constant with a shunt-connected field, and of course...
  2. hevans1944

    Hooking up deadbolt motor to TB6612FNG Stepper Motor Controller

    I will not provide you with a schematic. Follow the Application Note in the datasheet. Draw up your own schematic and post it here for comment. You just pick which one of the two H-bridge output channels you want to use, connect the two motor terminals to the two outputs of that channel, apply...
  3. hevans1944

    Hooking up deadbolt motor to TB6612FNG Stepper Motor Controller

    I was able to open the Toshiba controller datasheet in a Firefox PDF reader window. It didn't save properly (font problem?) but my free PDF Creator app was able to open and save the image. Looks to be a bit of over-kill to open and close a dead-bolt lock driven by a puny PM DC motor powered from...
  4. hevans1944

    Is this possible?

    Wow! Now all you need is some electronics expertise. Provide LOTS more information. What model synth? What kind of filter? Provide model numbers and schematics. Someone here can probably help you, but we need to know what you are trying to DO before offering advice on how to do it.
  5. hevans1944

    need help please

    Make a schematic drawing of the circuit you are trying to build, take a cellphone photo of it, and upload it here. Maybe then we can help you. The diode you specified is also available in reverse polarity packaging (1N1190AR) for mounting on an uninsulated heat sink with other diodes in a...
  6. hevans1944

    Can anyone recommend a simple linear VCO?

    That is exactly what the posted circuit tries to do. There are many sources of "error" that will affect the linearity, but in principle it works perfectly. The op-amps selected are good for this application: very high input impedance, low bias currents, decent slew rates, yada, yada, yada. If I...
  7. hevans1944

    Capacitors

    Using a capacitor to store energy to light up an LED is an exercise in futility, usually. Even if you "charge" it with a 3.3 V power supply, the energy you store will be quickly depleted, the voltage across the capacitor will decrease rapidly from its initial voltage, and the LED will quickly go...
  8. hevans1944

    Can anyone recommend a simple linear VCO?

    Well, there used to be a nice integrated circuit available from Intersil, the ICL8038 whose datasheet you can download for ideas. There may be a few of these still floating around on eBay and such. I used this IC in the 1970s to build a musical note generator by programmable division of a...
  9. hevans1944

    741 circuit amp wont turn on

    Post a schematic. Draw it on paper if you have to and take a picture.
  10. hevans1944

    I ask a never seen electronic part.

    Could you tell us what kind of laser pulser you are examining? Is it a commercial laser diode pulser? Does it use a transistor operating in avalanche mode? What are you trying to do with your laser pulser? Optical radar (LIDAR) perhaps? Fiber optical communications? Please tell us what you are...
  11. hevans1944

    I ask a never seen electronic part.

    Could be a 4.7 ohm power resistor. Have you tried measuring its resistance with a multimeter?
  12. hevans1944

    Connecting wires

    "When all you have is a hammer, everything looks like a nail." Your procedure will work. It won't look "pretty" or "professional". Safe is a relative term. If firmly pulled, the wires could slip out of your pliers-squeezed connection and the bare ends short against something. Soldering would...
  13. hevans1944

    Multisim - How do I find the Resonant Frequency (FR) on an LRC circuit?

    Thanks, @dorke! This is way cool stuff. Maybe I will come out of my cave and fire up one of the SPICE simulators I happen to have installed, just so I can keep up with the younger generation. Sure beats trying to compose equations and use Excel spreadsheets for graphing.:eek: Oh, wait! I don't...
  14. hevans1944

    Multisim - How do I find the Resonant Frequency (FR) on an LRC circuit?

    Hey, @dorke, hows come you asked for 200 points but the display only plotted 20? Nice that it "filled in the blanks" when plotting the sweep though.A linear magnitude scale would provide a more dramatic-looking resonant peak, as @Ratch showed in post #15. @Harley, please note the sharp reversal...
  15. hevans1944

    Current protection circuit

    Try this one. Should be available from distributors, or you could ask for a free sample from Allegro. Tell them you are a project developer and need a sample to test for proof-of-concept. Or just order the Allegro and the PIC from a distributor for fastest delivery. Samples can take forever to...
  16. hevans1944

    Current protection circuit

    There are several ways to disconnect the hall sensor (why is that necessary?) and interrupt current to the relay coil when the load current exceeds a preset level. When the "trip point" is reached, the relay de-actuates, causing it to interrupt the load circuit. Problem is, that function needs...
  17. hevans1944

    Multisim - How do I find the Resonant Frequency (FR) on an LRC circuit?

    Try narrowing your frequency sweep range to more closely bracket the resonance peak. The magnitude plot should look "curvy".
  18. hevans1944

    Multisim - How do I find the Resonant Frequency (FR) on an LRC circuit?

    Your method is correct, as are your updated results, even though in (C) you have FR = 468.333 Hz but used the correct value in the calculations. Now calculate XL, XC, and Z at the resonance frequency. I am "pretty sure" Multisim will allow you do a frequency-sweep simulation. Just set the sweep...
  19. hevans1944

    Finding C & L from XC and XL

  20. hevans1944

    Finding C & L from XC and XL

    I would have left a site that encouraged the posting of "condescending and insulting" responses too. And probably would never have gone back, even if someone here "recommended" it. For entirely different reasons, I no longer respond to questions on a popular site that solicits (and votes on)...
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