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  1. CDRIVE

    GPS NMEA, Failover Circuit upgrade attempt.

    Great find! That certainly is a mind blower! I'm putting those links in the same folder that I keep the MAX232. Chris
  2. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    A warning for anyone that stumbles upon this topic in the future! Don't expect any of these results if simulated in Spice. For one thing (unlike the real world) identical components in Spice are Absolutely IDENTICAL unless you edit their properties. Secondly Spice Voltmeters and Ammeters are...
  3. CDRIVE

    NPN transistor as switch for LED problem

    Try this. R1 can be as shown and will provide about 18mA of LED current. Raising it to 1K will reduce LED current to about 11mA. This assumes a RED LED. Chris
  4. CDRIVE

    GPS NMEA, Failover Circuit upgrade attempt.

    USB/Serial converters commonly output ±5V. The MAX232 inputs can handle up to ±30V. Early RS232 standards found data levels as high as ±30V. I'm still lost! Chris
  5. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    After viewing your schematics it confirms my suspicions. You're reply though leaves me speechless. Chris
  6. CDRIVE

    12v 3amp battery charger lead acid

    Dave, I like the circuit but why isn't D6 connected directly to the battery? Am I missing something? Chris
  7. CDRIVE

    NPN transistor as switch for LED problem

    Steve, I've never had to shunt a LED. Have you experienced that? Are you referring to situations with very high VCC or when using Germanium Transistors? :p Chris
  8. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    Reading back on my post I think I elevated the request to a demand. :D Chris
  9. CDRIVE

    Automatic Irrigation System

    Krimstix, please get in the habit of using multiple GND symbols instead of running a GND buss all over your schematics. It'll make your schematics much easier to follow. It will also reduce schematic errors. Generally we like to see the positive ( + ) supply rail on the top of the page and...
  10. CDRIVE

    Automatic Irrigation System

    Good point Harald. In that case he may want to increase the value of R3 (1KΩ) too. Chris
  11. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    You have 77 posts at the time of this posting. Not all of them are in this topic but after that many posts we shouldn't have to get on our knees an beg for a damn schematic! :mad: Sorry for the rant but you've been asked repeatedly and as far as I can see you've totally ignored our pleas. Chris
  12. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    That was impressive! I hope Steve wasn't driving while computing and texting that! :) Chris
  13. CDRIVE

    GPS NMEA, Failover Circuit upgrade attempt.

    I don't want to see you smoke more of them so double check the polarity of the other caps too. I've been staring at your schematic to the point of bleary eyes but I just can't see what's popping the MAX. What's the voltage rating of those caps? Have you Ohm'd them out to insure none are shorted...
  14. CDRIVE

    Automatic Irrigation System

    Upon a second look I'd also increase the value of Pot R1 to 5KΩ. This is to insure you can swing pin2 (Trig) low enough to trigger the 555. Off the top of my head I believe the 555 triggers (Output pin High) when this voltage (Vtrig) goes below 1/3rd of Vcc. Chris
  15. CDRIVE

    Automatic Irrigation System

    Your Vcc (V1) polarity is reversed. Chris
  16. CDRIVE

    LEDs in parallel don't consume sum of individual currents??

    I missed this quote. This discrepancy is far beyond burden voltage issues. Only a schematic is going to clear this up. I hope that when seanspotatobusiness says parallel LEDs he doesn't mean Anode to Anode, Cathode to Cathode!!! Chris
  17. CDRIVE

    Switching leds

    My Tina library has 3 pin common cathode models and a 4 pin (independent Anodes & Cathodes) dual LED. I used it and tied the Anodes together. The rest of my circuit just echos the existing circuit he posted. Including the oddball 4.7KΩ current limiting resistor in the Drain. He can change the...
  18. CDRIVE

    Help with sensing a stopped sprocket

    Yes, sometimes it isn't pacification. Anyway, let us know how Minder's circuit works out for you. We always hear from OP's when things aren't working out but when they do work they disappear like the relative you lent money to. :) Chris
  19. CDRIVE

    Easy Machine To Wind Transformer

    Javier, if you decide to build one post your progress in this thread. It's a project that can be relatively simple or (as seen in some of those vids) complex and sophisticated. Thank you for the blessings. Chris
  20. CDRIVE

    Help with sensing a stopped sprocket

    Ha, so was I. Electronics contractor at a hospital. I have to confess that my favorite pacification lines were... Yup, I'm on it. Waiting for an obsolete part that can only be procured from the remote regions of Siberia. Yeah, I know you needed this last week but the ER has priority. Your...
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