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  1. CDRIVE

    Data sniffing from a RS232/485 network

    When you say "Data Sniffing" are we to assume a second PC that's reading the data somewhere along the line? I would highly recommend reading "Serial Port Complete (2nd edition) by Jan Axelson. She's an iconic figure on all topics of PC and uC data communication. http://www.lvr.com/spc.htm...
  2. CDRIVE

    Capacitor

    It's next to impossible to recommend suppliers when we don't know your location. Your user control panel provides box to insert this information. We don't want or need your address, county or town but country and state/province is very helpful. Chris
  3. CDRIVE

    Amplitude and Frequency

    Duke previously explained how to resonate a glass in order to measure its resonant frequency. What you did here is not what he described. Frequency counters, whether real or PC based require a reasonably steady signal for at least a few seconds or it will return erroneous results... And yes...
  4. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    That's not surprising. The higher the freq the lower all R values have to be for non static portions of the circuit. Yes, this translates into increased current. Chris
  5. CDRIVE

    The magic of Colloidal silver

    Ouch! I always find it sad when debates turn ugly. Wishing someone dead is really over the top. :( Chris
  6. CDRIVE

    The magic of Colloidal silver

    Float in the sky? Yes, this thread is a couple of months old and I did miss your post while traveling. FYI, I cut my teeth on RF circuitry where connections directly to ground are imperative. Drawing GND as such conforms to this practice far better than a ground buss/rail. I also don't like...
  7. CDRIVE

    Amplitude and Frequency

    I guess I should rephrase my statement. All my PCs employ phantom powered mic jacks to accept unpowered electret mics. The DC that the electret requires is derived from the PC mic jack. I've always assumed that all modern PCs are wired this way. So,.. if an external coupling cap is used...
  8. CDRIVE

    Amplitude and Frequency

    I don't think he needs a coupling cap either. The PC's mic input is wired to take electret mics directly. If you couple an electret through a cap it won't work properly without providing battery power through a limiting resistor. Chris
  9. CDRIVE

    RF project

    I would think that FSK (Frequency Shift Keying) would lend itself well to byte data transmission. Chris
  10. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    Kris, thanks for posting the schematic. OK mates, here's my Tina results of iimagine's first circuit. After running this I did plug in 100pF (probably excessive) between various nodes. As expected some had little to no effect while others certainly destroyed the linearity. I would...
  11. CDRIVE

    Amplitude and Frequency

    This is one of the issues I had with the Myth Busters episode. The speakers they used were bird baths,... sized for a flock of Condors!! :rolleyes: Chris
  12. CDRIVE

    AC circuit and relay

    Well yes, if someone doesn't know what they're doing it certainly is. On that note I'm not my brother's keeper. I don't want to be and I don't want my government to be either. That said it's a nanny state world. I'm a Redneck at heart and I find joy in watching Youtube videos of crackers using...
  13. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    Would one or both of you be kind enough to post your schematics only? I want to copy and paste the image into Tina, where I will create my own schematic. I want to sim them to see if my results are the same as yours. Chris
  14. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    If I left click on your thumbnail I get an image that fills 2/3 of my screen. If I right click and open in a new tab I get an image that fills my entire screen. If I then click it again when the magnifying glass has a '+' in it it's so large that only 50% of the image can be seen without...
  15. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    I just took a peek at the specs of your scope. I should have done that before but I didn't. It's a USB model with Input = 1Meg & 25pF. I didn't see any mention of 10x probes with it. Anyway, hang a 1M resistor across your cap in LT Spice to see what happens. Chris
  16. CDRIVE

    7 Transistors Triangle Wave Generator (650Khz)

    I wouldn't be so quick to dismiss your LT Spice results. It's far more likely that the discrepancies lie elsewhere as Kris stated. What's the input resistance/cap of your scope? Are you using a low cap 10X probe. What's the scope coupling - AC/DC? If your using a 10x probe did you adjust the...
  17. CDRIVE

    Amplitude and Frequency

    Wow! There's nothing more clever than using a heavily patterned background to really bring out the details of the object you're photographing. :rolleyes: Sorry,.. I couldn't help myself! :D Chris
  18. CDRIVE

    DPDT On-Off-On for options

    Perhaps this pictorial will help.. Chris
  19. CDRIVE

    AC circuit and relay

    Heck, I knew I'd draw this anyway but please read my disclaimer in my signature. ;) Chris
  20. CDRIVE

    AC circuit and relay

    Judging by your metering description I would say that the two nodes that you're measuring are across the wall controller (thermostat) contacts. Thermostat contacts might be a misnomer here because the battery powered thermostat may be totally solid state with no electromechanical contacts at...
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