Model Power Signals

Discussion in 'FAQs' started by Big Don, Feb 13, 2003.

  1. Big Don

    Big Don New Member

    Last week I a bought a pair of crossing signals made by Model Power and there were no instructions in the box.

    I have two questions:

    (1) What power source is required to power the signals?

    (2) Is there a detector I can buy/make to trigger these signal lights automatically rather than using the switch that comes with

  2. shamus

    shamus Registered Member

    Hi Big Don and welcome to the gauge.

    Are these crossbucks? if so, then the drawing below will make the lights flash on and off.


    Attached Files:

  3. Big Don

    Big Don New Member


    Thanks for welcoming me to this site --- I am finding it extremely useful so far.

    Are you sure the circuit you attached isn't for a WMD? :D

    Now I REALLY wish I had paid attention in that Electric Circuits course I took in university (and barely passed!).

    OK --- here are my comments and questions:

    - I believe we're talking 16 volts DC ---- correct?
    - If memory serves me correctly, what you have marked ASAMA and TDC are capacitors --- correct? What do ASAMA and TDC mean??
    - I have absolutely NO idea what you have marked as 9XC/4ne555P/5 Malaysia is!

    Why do I have this nagging feeling that I'm having my leg pulled ;)


  4. shamus

    shamus Registered Member

    Hi Don,
    I am not an electronics expert myself, all I know is the drawing works for a flashing set of lights. I myself use it for my crossbucks.

    Here it is.


    Attached Files:

    • f.jpg
      File size:
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  5. cidchase

    cidchase Active Member

    Hi Don,

    2 capacitors
    1 555 timer chip
    1 1n4001 diode
    1 resistor 300k if it's orn-blk-yel-gold
    Looks like a very simple and effective flasher :D :D

    Paul, can you verifyy the color code on the resistor?
  6. Big Don

    Big Don New Member

    Thanks Shamus --- BTW, the code for a 300K resistor chip is correct.

    Where did you buy the timer chip in the UK? The other components should be readily available at radio shack.
  7. Paul Davis

    Paul Davis Member

    The 555 has to be the most common (hobbiest) chip in the world. If your local radio shack doesn't carry it then I'll eat Shamus's layout.

    You could also use a 556 it's just two 555's in the same package.
  8. Big Don

    Big Don New Member


    You were right --- I picked up a 555 Timer IC at the local Radio Shack yesterday.

    If you've used these before, perhaps you can answer one question for me.

    On the back of the package, there is a circuit diagram showing the 'guts' of the timer and indicating what each of the 8 contacts is for: ie

    1 = Ground
    2 = Trigger
    3 = Output
    4 = Reset
    5 = Control Voltage
    6 = Threshold
    7 = Discarge
    8 = +Vcc

    However, there is nothing to indicate which contact is which. Do you or Shamus happen to know if there is a way of determining which is which by using a multimeter??


    Big Don
  9. TerryR

    TerryR Member


    There will be a white dot or a recessed circle on the top face of the chip. It is next to pin 1. From there, the rest will be in the order shown on the back of the package.
  10. cidchase

    cidchase Active Member

    555 PIN LAYOUT
    Use the "notch" at one end for orientation

    Attached Files:

    • 555.jpg
      File size:
      6.5 KB
  11. Big Don

    Big Don New Member

    Thanks Gentlemen --- there is a recessed dot at one corner. I'm off to the races.

    Big Don
  12. Freelancer

    Freelancer Member

    If you are like me, and all of this electronic talk is going over your head you can try this web site.
    I got a flashing crossbuck set. It came with an infra red detection system, so that when the train crosses the beam it signals the flashers. I am very impressed with it. There are also quite a few different electronic gadgets similar to it. Good luck.

  13. Pitchwife

    Pitchwife Dreamer

    One thing I might add about the capacitors is in referance to the voltage rating. You can always use a voltage rating higher than what your circuit is using. In a circuit that is running 12 volts, a capacitor rated at 100 volts will work as fine as one rated at 35 volts. If you use one that is rated below the working voltage be prepared for some fireworks. :D :D
    Also, be sure to observe the polarity of eletrolytics.
  14. Paul Davis

    Paul Davis Member

    I'd make sure your capacitors are rated at least twice the voltage you expect them to handle. Manufaturers tend to be a little over optomistic when they state the values.

    As for the electrolytics, if you do stick them in backwards and they explode you get a big ball of stringy fluff stuff which I'm sure would be good for modeling something.

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