Search results

Search Forums New Posts
  1. CDRIVE

    My Cousin Vinny (Run capacitors and motor direction)

    Hi Steve, I considered Google but I figured that hits would return typical reversible induction motor wiring instead of the anomaly I'm looking for. I guess I should have tried.. You did and it paid off! Got a link? In the interim I'll give it a shot. Thanks, Chris
  2. CDRIVE

    My Cousin Vinny (Run capacitors and motor direction)

    This is one of those times that the title choice may have been less than descriptive. This is something I bitch about often, but I couldn't help myself! Perhaps "Induction Motor Problem" would have been more apropos. Hey guys, don't let me down here. My cousin Vinny is a fellow ElectronHead...
  3. CDRIVE

    My Cousin Vinny (Run capacitors and motor direction)

    I received a phone call from my cousin Vinny today. It seems he has a weird problem with his home's air handler. The Cap Run SPH motor inexplicably runs backwards at times! My question is this... Have any of you guys ever experienced this? Would a shorted or very leaky run cap cause this? I...
  4. CDRIVE

    coupled LC resonance circuit

    Ha! I love that!! Hey guys, as much as I loath reading directions it sometimes is necessary. I did a quick perusal of the PDF links in that article and things are much clearer now. I highly advise anyone interested in this thread to read them. As it turns out the author is fully aware of...
  5. CDRIVE

    coupled LC resonance circuit

    Dave, that's the hitch! There is NO antenna and virtually NO load! If he's reproducing the setup in his link the tuned circuit is being used to step up the RF voltage to (unloaded) extremes. This high RF voltage just sits on ionizing electrodes not intended to radiate like an antenna. At least...
  6. CDRIVE

    coupled LC resonance circuit

    Hey Dave, I investigated it a bit further. This link expands a bit on what you posted. http://en.wikipedia.org/wiki/Coaxial_cable#Choice_of_impedance I want you to know that this revelation really sucks for me. I sure am glad that we didn't have internet forums for the entirety of the last...
  7. CDRIVE

    coupled LC resonance circuit

    I'll take your word for it Dave but it seems like quite a big coincidence that a 1/4 wave ground plane has a natural 50 Ohm input Z. By the way this stuff wasn't always standardized. I have a very old 1932 signal generator made by General Radio for the U.S. Navy. It originally had a 10 Ohm...
  8. CDRIVE

    coupled LC resonance circuit

    Electronics, like most scientific fields of study, is made up of subsets, that in their own right can be viewed as their own field of study. RF Theory & Design is definitely a valid subset. Within the RF subset, Antenna / Transmission Line Theory & Design could and does fill textbooks...
  9. CDRIVE

    coupled LC resonance circuit

    Your circuit does not reflect the values used by the author. All comments and component names below refer to the authors schematic. I converted all series and paralleled components to their equivalent (effective) values. I varied C3 from 20pF.- 30pf. This produced only relatively small...
  10. CDRIVE

    coupled LC resonance circuit

    Thanks for posting the link. The purpose of C4 (0.1uF) makes much more sense now. It's a DC blocking cap when DC bias is injected into the system. Have you spiced Fourier (spectrum analysis) or swept AC Analysis yet? Chris Edit: I can't find any reference to the value of R1 that says...
  11. CDRIVE

    coupled LC resonance circuit

    If this is an online journal please post the link. I want to see which node the author is using for an output. Are you picking the signal off across R1? Chris
  12. CDRIVE

    coupled LC resonance circuit

    Where did you find that circuit? Chris
  13. CDRIVE

    Can I use heat duct vent as ground for a radio?

    That would be true if it was 1970. Today it's doubtful that the radio is not battery/wallwart powered. In either case there would not be a connection to earth. And yes, he's talking about grounding the chassis/neg rail of the radio for better AM reception. Chris Edit: Don't feel alone...
  14. CDRIVE

    help with picaxe

    Yup, that link explains it. Chris
  15. CDRIVE

    coupled LC resonance circuit

    Personally, I think demonstrating the effects of two resonant circuits that are separated by close frequencies is best demonstrated and spiced using two parallel tanks that are loosely coupled to each other. It will produce the classic "bandpass" response curve where both resonant frequencies...
  16. CDRIVE

    Can I use heat duct vent as ground for a radio?

    You can test the vent for ground connection using an Ohmmeter connected between the vent and your receptacle ground pin. Note!! When I do this sort of test I always place the meter in AC Voltage mode first. This way you can test for any anomalies before placing the meter in Ohms mode. ;)...
  17. CDRIVE

    Roseanne Roseannadanna.. "Did ya ever wonder...."?

    Uh, as luck would have it and if the manual did mention the magic button, that's all it would have done. There'd be an image with an arrow pointing to "BUTTON". :rolleyes: Chris
  18. CDRIVE

    Roseanne Roseannadanna.. "Did ya ever wonder...."?

    I thought I'd start this thread as something to be appended. I think it's something we've all experienced at one time or another. Let's start with the topic of HELP files. Did ya ever notice that no matter how complete your new software's help files are the items you're needing help with are...
  19. CDRIVE

    NEW BIKE!

    Post some photos. Chris
  20. CDRIVE

    help with picaxe

    I missed this earlier. Emitter Followers don't require a base current limiting resistor. Chris
Top