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  1. CDRIVE

    PIR operated DC motor project odd behaviour help

    That's not what I drew. GSM battery (-) should be connected to Opto jack (-) Black. Chris
  2. CDRIVE

    Serial communication problem.

    This and its associate topics has me at a point where I've lost track of where it all started. We've moved through Picaxe, PICs, MAX232's and all of it permutations. I think GSM was somewhere in this mix too. Sooo.. are looking for a general purpose terminal app or would a utility that's...
  3. CDRIVE

    Serial communication problem.

    When you say "until interrupted by the user" what does that mean? Are you referring to a response returned by the receiving device or simply a "Repeat" option on your terminal software? If the latter it'll need a timer function that repeats the message typed every 'n' seconds until disabled...
  4. CDRIVE

    Oscillator

    Dork, you beat me to it. I added a flyback diode and cap to clean up the output. Though excluding them makes an effective alarm clock event. Ya just need to add two wires taped to your body. :D Chris
  5. CDRIVE

    Oscillator

    One of my first oscillators. :) Chris
  6. CDRIVE

    PIR operated DC motor project odd behaviour help

    Hey, I forgot to mention.... If you're interests continue down the road of electronics you really need to learn the art of cannibalization and re-purposing. This can be imperative for the young (financially deprived) or those in areas that components are difficult to obtain. :) Chris
  7. CDRIVE

    PIR operated DC motor project odd behaviour help

  8. CDRIVE

    PIR operated DC motor project odd behaviour help

    This is an alternative to timer board surgery. I indicate a 2N2222 but just about any general purpose small signal NPN will do. Chris
  9. CDRIVE

    PIR operated DC motor project odd behaviour help

    OK, that indicates that the GSM switches the vibrator motor from the (high side) positive rail. I don't think you want to do any exacto-knife surgery on your timer board. So I'm going to give you a one transistor interface. I'll post it within the next hour. Chris
  10. CDRIVE

    PIR operated DC motor project odd behaviour help

    OK, that explains the seemingly strange behavior when connected to your GSM ringer output. The next test is to determine if the vibrator motor is Low or High side switched. Low Side switching is more common in electronics circuitry. GSM (High / Low) Switching Test: (1) Turn your GSM on. (2)...
  11. CDRIVE

    Tamperproof sink

    I think I love this topic. Humans that have been soooo unfortunate to have never loved pets will never understand why anyone would go to the lengths that this topic entails! I feel fortunate to be in the camp that does.;) Chris
  12. CDRIVE

    PIR operated DC motor project odd behaviour help

    Hello Ivan, I'm reasonably sure that we went through this before but we're going to do it again. (1) Disconnect the GSM from the timer module. (2) Apply power to the timer module. (3) Place your DMM on DC Volts scale. (4) Measure voltage present across the opto input jack. (5) Record voltage...
  13. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    What's your point? Chris
  14. CDRIVE

    555 timer one shot question

    Here's one way of disabling auto-repeat in Windows. Perhaps Apple employs something similar? https://answers.microsoft.com/en-us/windows/forum/windows_xp-performance/can-you-disable-the-keyboard-autorepeat-function/ce1b29bc-544b-e011-8dfc-68b599b31bf5?auth=1 Chris
  15. CDRIVE

    555 timer one shot question

    What AG pointed out (switch bounce) is true but a 555 monostable should eliminate that. The edge trigger example I posted is not a complete circuit. It only demonstrates what the waveform at the Trigger Pin should look like vs the S1, R1 voltage node. The Output Pin characteristics you're...
  16. CDRIVE

    555 timer one shot question

    You can "Edge Trigger" a 555 like this. It will not re-trigger until S1 is reopened and then closed again. Chris
  17. CDRIVE

    FM inductors

    Dave, I think most would question themselves as to exactly how that happened. It's still happy hour here. So I'll just try to figure it out later. :):confused: Chris
  18. CDRIVE

    FM inductors

    Being owner of two topics that are essentially asking the same question will not win you our favorite "Nube Of The Month" award. o_O FM Transmitter Power Chris
  19. CDRIVE

    FM transmitter power

    An ignition coil, sometimes called a spark coil is intended to provide the spark required to ignite the compressed air/fuel mixture within the cylinder of an internal combustion engine. It also makes one hell of a wide band transmitter! Does the name Marconi ring a bell? Besides that bit of...
  20. CDRIVE

    FM transmitter power

    There's a huge chasm between the name of that .gif and the circuit design. A far more appropriate name would be "Basic FM Transmitter.gif". Chris
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