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  1. CDRIVE

    add to existing circuit to complete buzz wire game

    Your question would only be pertinent if the game is timed or winning is determined by not exceeding a set contact count within a set time period. Another option would be making it through the gauntlet with the objective being to turn on the green led at the end of the gauntlet and doing it...
  2. CDRIVE

    PIR operated DC motor project odd behaviour help

    Let's see if I can get the image pasted this time.. Chris
  3. CDRIVE

    PIR operated DC motor project odd behaviour help

    This thread spawns more questions than answers. What are the Red & Black conductors coming off the left side of your PIR module? Chris
  4. CDRIVE

    PIR operated DC motor project odd behaviour help

    Linear Voltage Regulators must be powered by a source voltage higher than the Vreg voltage it's spec'd at. Take a look at this simulation of a 7808 regulator and tell me if you understand it. VS1 is a voltage source (Input) being swept from 0V to 20V. Observe the input voltage (X Axis) versus...
  5. CDRIVE

    Problems with sound circuit on a toy train

    Flash, the single most unwelcome word in electronics vernacular is .... "intermittent". :eek: Chris
  6. CDRIVE

    PIR operated DC motor project odd behaviour help

    It's a miracle that thing is working at all. First off I had no idea that the only thing the regulator is regulating is the motor voltage not the entire PIR circuit. Besides that your regulator is not wired properly, as I don't see a GND connection between the motor and the regulator's GND pin...
  7. CDRIVE

    Problems with sound circuit on a toy train

    Me too. Woo Woo! Chis
  8. CDRIVE

    PIR operated DC motor project odd behaviour help

    This is going to leave this thread supposedly resolved with more questions than answers. For one thing how and why does an 8V linear regulator output 4.8V and moreover do it with only 5V input? :confused: Are you omitting important details, like your no longer using a 5V supply? Chris
  9. CDRIVE

    PIR operated DC motor project odd behaviour help

    OK, I had to go back to your original post to verify this. You didn't specify this but should we assume that only the multimeter is connected to the output (no motor) when measuring? Did you try driving only a resistive load? You never did answer my questions about your motor specs. Please post...
  10. CDRIVE

    PIR operated DC motor project odd behaviour help

    According to the link and image I posted there is a sensitivity adjustment. Actually I'd be surprised if it didn't. Chris
  11. CDRIVE

    Speed control (drum sander) repair

    Triacs usually explode for a reason. Have you tested that motor? Chris
  12. CDRIVE

    Help converting wireless mouse into wired

    Perhaps easier said than done in his area of Pakistan? :) Chris
  13. CDRIVE

    PIR operated DC motor project odd behaviour help

    Should we assume that you've played with the sensitivity adjustment? Also, what's the motor current draw at this voltage? BTW, welcome to Electronics Point. Chris
  14. CDRIVE

    PIR operated DC motor project odd behaviour help

    From what I've been able to google this PIR has an adjustable (they call it) "Time Delay" feature that's adjustable from 5 to 360 seconds. I'm not sure but I think they're describing adjustable "Latch Time". Scroll down to about mid page for image location of adjustment...
  15. CDRIVE

    Transmitter circuit operation explanation

    Damn! As I typed that there was a little voice saying "Are you sure of this? Check this FET out before committing yourself ". I should have listened to the little voice. Either that or the little voice should have been louder! :) Looking again at the schematic symbol I shouldn't have made such...
  16. CDRIVE

    Transmitter circuit operation explanation

    Because it's not a MOSFET. It's a dual gate JFET. Unlike N Chanel MOSFETS JFETS conduct between the Source & Drain with no bias on the Gate. Their characteristics more closely resemble that of a Vacuum Tube than a MOSFET. R8 (as small as it might be) provides some negative bias between the Gate...
  17. CDRIVE

    Variable Frequency Op-Amp Astable

    Better yet add a fixed resistor so Rx is never zero when either Pot is at minimum. Chris .
  18. CDRIVE

    Variable Frequency Op-Amp Astable

    After further thought this would be a preferable design. VR1's value is ~ 10 times > than VR1 but it could be a much higher resistance ratio if you like. Even a 100:1. You'll can play with these values to find what you like. Chris
  19. CDRIVE

    Variable Frequency Op-Amp Astable

    Rotary switches aren't as common as they once were but you can still get them. That said I used a SPDTCO switch to provide a method of dividing your frequency range into 3 switch positions. When the switch is Off (center position) only C1 is in the circuit. This will be your highest freq range...
  20. CDRIVE

    Noob Soldering Problem - Which Wire To Use?

    Hop, my Dad bought me one of those contraptions (still have it) over 50 years ago. I didn't have the heart to tell him I'll never use it. BTW, I've never used the stop screw on the Miller. Totally feel and experience. On the other hand the Teflon insulation you mentioned is a different animal...
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