SNAPPER capacitor discharge

Model Railroader Layouts and layout building
1

I am trying to use a SNAPPER from my old layout but do not have any literature
showing how to wire it up. My unit has a wire from each of of the out put posts
but one of the wires has a small resistor on it. The in put side from the ac side of power pack i understand but the out put side is the question. Is the resistor necessay?/ Where exactly do the out put leads go?/

Any for this old man would be appreciated

jim

2

Not familiar with that particular unit, but normally CD boxes charge up a capacitor through a resistor, then discharge it directly into the switch machine. I would expect the resistor to be on the INPUT side (are you SURE it’s an AC input?) Input and output probably have one side common to both.

3

I’ve built a few CD units of my own and the output leads go to the switches controlling the turnout machines.

I don’t know if the resister you are talking about belongs there or not. I would guess not, judging from the photos I’ve of a Circuitron Snapper. The resistors that are required for charging the capacitor are mounted to the circuit board and not hanging off the output leads. I never bought one so I can’t say for sure.

Hopefully someone that has bought one will see your post and send you a photocopy of the instructions. I tried searching the web to see if the have a web site but apparently they don’t. Perhaps a (good) hobby shop or Loy’s Toys can help. Maybe check with the N.M.R.A.'s Kalmbach Memorial Library. The have some old kit instructions.

Good luck O.M. Jim!

4

Hi Jim,

From the ‘Snapper switch machine power supply’ instructions:

Connect two wires from the terminals marked [in] to the accy terminals of a power pack or any SMALL 25 volt or less transformer…snip… Connect the terminals marked out to the switch machine controls with 18ga or heavier wire.

So, no resistor involved here!

As to the outputs:

  • one side to ‘common’ on the switch machine(s)
  • the other side goes to both of the other wires on the switch machine, BUT, thru’ momentary (pu***o make) switches - ie, two ‘button’ switches per turnout machine… I think that makes sense, but sure wish I could post the diagram I’m looking at :slight_smile:

HTH,
Ian

5

I’m wiring one now to a lay-out in progress, we called them years ago “zappers” because of the sound of multiple twin coil swithes being thrown together. Are you sure it’s a resistor and not a diode? The trick with mine, which I built from surplus electronic parts requires a diode for current flow. It has two post one in one out, they are to be wire in line with the diode in between so the current runs one way only. These units are great if you want to throw multiple swich motor at once. i.e. a yard ladder or double cross-over etc.

Good Luck,

James

6

Thanks guys. This hepls and I should be able to “make it work” from here. LONEWOOF you were right I did transpose the input-output in my msg! I will also call LOY today good idea!

Again thanks all

Jim

7

Have in hand direction sheet from Snapper, a 4.7 ohm resistor is supplied for use on the “in” or supply side IF the power supply used is one (1) amp or greater. if the transformer used is less than one amp. the resistor is not necessary. Hope this help. Jim