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  1. hevans1944

    What is this Blue Component?

    I wish I had a quad I could stand on and fly. What a rush that would be! Glad to hear you got your little one flying again. You might want to coat that inductor with a blob of clear RTV (like the stuff they placed on the crystal can) and let it cure overnight. Might prevent it from cracking the...
  2. hevans1944

    PWM solenoid use

    I recently happened upon some free samples from Linear Technology that I forgot I had. These are Universal Timing Devices from LT's TimerBlox product line. They have a website that walks you through the application design procedure. This may be the easiest solution yet to generating a constant...
  3. hevans1944

    What is this Blue Component?

    I suppose you could temporarily remove the coil from the new board and measure its inductance if you can find a meter to do that. The core material may be important, depending on how the thing is used, but I don't know how you would determine which core material is used. And, as you discovered...
  4. hevans1944

    PWM solenoid use

    So the 1N4001 diode and the 4.7 Ω resistor would have to added to whatever circuitry you attached to the connector. I assume you have an extender cable to go between the transmission connector and your purpose-built box. Do you have a connectors on both ends of this cable? Or will you just...
  5. hevans1944

    What is this Blue Component?

    You could also try ordering a replacement board for nine bucks from here. Free shipping, but latest version may not work with your Transmitter.
  6. hevans1944

    What is this Blue Component?

    I would try soldering the wires back together... strip off a short length of the enamel insulation with fine sandpaper or a razor blade, being careful not to nick the wire, tin the ends with solder, then butt-solder the ends together. What have you got to lose, since it's broken anyway? Or if...
  7. hevans1944

    What is this Blue Component?

    Try to glue the two pieces back together with superglue (cyanoacrylate adhesive).
  8. hevans1944

    PWM solenoid use

    You posted a schematic showing the wiring interface between the transmission and ...something. I'm not sure if the "something" is the ECU or another "black box" transmission controller like the SuperShifter box you also posted. In any case, the diagram shows one side of the solenoid valve...
  9. hevans1944

    AC circuit (120v single phase) smooth to a10 sec. average voltage sine wave

    @David Kimbley : It is not easy converting signals from the frequency domain back into the time domain. Depending on how the DSP implements the digital filtering, you must preserve the phase information to re-construct the time-domain signal that produced the frequency domain signal you are...
  10. hevans1944

    PWM solenoid use

    Adam, I was referring to my original suggestion as being too complex... I didn't actually provide a schematic like you did, just a verbose description of how to use a sawtooth waveform, a comparator, and a flip-flop to generate a PWM signal. I am sure your circuit will work too. There is always...
  11. hevans1944

    Inject sound to a phone landline

    Sounds like @Externet has some experience with the telco service and 'phone patches (maybe as an amateur radio operator, back when hams did phone patches?). A true bi-directional phone patch requires a hybrid coil connection to separate the incoming and outgoing voice signals, with just a little...
  12. hevans1944

    B&K Precision better than Tektronix ? (Oscilloscopes)

    Hmmm. If you purchase the B&K from Newark, you have to buy at least ten of them. I have used B&K products and generally was happy with their performance. However they are made in Asia, documentation may suffer in translation to English, they are subject to obsolescence by being replaced with a...
  13. hevans1944

    AC circuit (120v single phase) smooth to a10 sec. average voltage sine wave

    Well, David K, as a mathematician you can look at this in the frequency domain instead of the time domain. The distorted input sine wave has frequency components centered on the power line frequency with some nearby "sidebands" caused by distortion, plus some higher frequency components caused...
  14. hevans1944

    PWM solenoid use

    In an earlier post I mentioned there was a simple way to obtain a PWM signal directly from the output of a 555 timer. Here is the circuit schematic: The above image was copied from here. The two diodes labeled "DUG" are unspecified germanium diodes in the original design, perhaps used there...
  15. hevans1944

    PWM solenoid use

    Vds is the Voltage applied between the drain and source terminals of the MOSFET. It is specified on the device datasheet as the maximum voltage that can be applied when the MOSFET is off. I have attached an application note from a semiconductor manufacturer that will help you read a MOSFET...
  16. hevans1944

    Homemade Capacitor

    @Lavaguava in post #1 provided the formula for calculating capacitance. Plug and chug.
  17. hevans1944

    PWM solenoid use

    If you create an astable (free-running) oscillator using a capacitor, two resistors, a diode, and a 555 integrated circuit timer, the voltage across the timing capacitor will be "ramp like" as it charges, and then quickly decay back toward zero, through a diode connected between the capacitor...
  18. hevans1944

    simple circuit drawing software

    What I have done in the past is to print out the schematic and go over it with a yellow highlighter, marking each connecting wire and writing down the node to which it connects to form a netlist. You could do this with a spreadsheet program too, for recording the net list, but the highlighter is...
  19. hevans1944

    PWM solenoid use

    Mebbe so, but I refuse to race my Fords lest the wheels fall off... or worse. Actually, the wheels DID fall off of my first Taurus station wagon... in a parking lot, thankfully, and not on the highway. Something to do with not maintaining the rubber boot protecting the constant-velocity...
  20. hevans1944

    PWM solenoid use

    Only after the wheels fall off! My 2002 Taurus station wagon has 250,000+ miles on it (purchased it used) and my 2002 Ranger truck has more that 50,000 miles on it (purchased new). Periodic maintenance of any vehicle will extend the usable life.
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