How to wire in a snapper?

[rrinker]

 Hopefully it is all wired in and working by now. Based on the design, which looks the same as the one I built myself over 40 years ago, the answer is "pretty fast" as that is the purpose of the transistor in the circuit, to allow fast recharge of the cap.

                                          --Randy

 

[ModelWarships]

Did you ever get an answer to your question of recharge time?

[Tophias]

Good timing for this post as I too will be installing a Snapper this weekend.  My quick question is how long does the Snapper circuitry take to recharge the capacitor, so as to be able to throw another turnout? (Obviously a question from an electrically challenged person! ).  BTW, we decided to install a Snapper due to issues with our latest project of adding signaling/turnout direction indication using PECO PL-13 auxiliary switches on Peco PL-10 switch machines. Our current home power supply throws the Pl-10’s fine, but the aux switches fail to make contact sometimes.

[rrinker]

 By the time you let go of the button, because oof the short pulse nature of the CD supply, there won;t be much current flowing in the coil of the switch motor to provide a serious spike when you let go of the button. Not sure of the exact schematic of the Snapper but it appears to have approximately the same aprts as the homemade unit I had, which serverely limits current flow through the switch motor after the capacitor discharges - not even enough to make them warm. That way even if the button sticks it won;t fry the motor. Common value for the resistor in a few circuits is 2.2K, with an 18VAC input that's less than 1ma across the coils if the button is held, or freezes. Any BEMF jolt from that is going ot be pretty low energy.

                                                  --Randy

 

[Overmod]

rrinker

... and peak can not go above the capacitor rating.

There is that.  I was confusing inductor spike without thinking enough.  

[rrinker]

I'm not about to risk my oscilloscope to actually measure it, I just know mine worked, worked well, and never ever fried the delicate Atlas N scale solenoids, so the beefier HO ones should be no problem. 

Unless you run rather heavy wiere (I used the 20-22, whatever the stuff they sold in hobby shops with 3 conductors, to extend the runs), between the internal resistance of the solenoid and the thing wire - you're clamping the voltage pretty good. ANd peak can not go above the capacitor rating. In fact the peak, if fed from an 18V AC source like mione was, would be 1.4 * 18 less the diode drop, under 25V. Who needs measuring tools, you can calculate this stuff 

                                            --Randy

 

[Bis]

I have know idea, nor would I know how to measure it. It definitely makes the turnout more lively.

[Overmod]

Bis

I thought being retired meant I would have all this spare time to work on fun things

You probably thought honeydew was a melon, too.

(Just for the record, and not at all to contradict Mr. Rinker, what I was saying about "surge suppression" was to clamp OVERvoltage -- very high spikes, not the majority of the short, effective capacitive discharge.  Has anyone measured or graphed the voltage over the ms. range of one of a Snapper's delivered 'shots'?)

(Confession: I was something of a recidivist quarter-shrinker in a previous life.  Mike Lehman knows what that is for...)

[Bis]

Yes, my wife is going with me to the Tyler Tx. Train show tomorrow but is going to wait outside and read a book. Which is fine, gives me more latitude in shopping.

[mbinsewi]

Oh yea ! thats the part about "Honey, we'll have so much more time together". , meaning you just lost most of the time you thought was yours.   Mine loves to go to trains shows, and such, I got lucky there.

Mike.

[Bis]

Update, got the Snapper hooked up. What a difference. Should have put one in years ago. As to free time since I retired. I seem to have had a lot more time for trains and reloading before my wife retired.

[mbinsewi]

Bis

I thought being retired meant I would have all this spare time to work on fun things

You do, if your just recently retired, you'll learn. Trust me !

Mike.

[Bis]

Thanks for the inputs. I got about half way thru the wiring when something came up. I thought being retired meant I would have all this spare time to work on fun things

[rrinker]

 No need for any of that, the pulse is extremely short and shouldn;t damage anyone's switch machines. I built my own that had at least as big a capactor as the Snapper and used in on Atlas N scale snap-switches, which were notorious for being easy to burn out (just look at the control box sideways and it would latch closed and fry the motor). Never had one even slightly dmaged after installing the CD supply. Putting surge protection in line with it defeats the purpose - you WANT a high energy but very short pulse. The circuit I built also had a large resistor to keep the capacitor inrush from shutting down the power pack - it also served to keep the current flow through the machines very low if the button got stuck, not enough to actually melt one

                         --Randy

 

[Overmod]

Seems to me you'd want to wire some kind of varistor in the line going to the switch machine to clamp the voltage potentially transferred off the caps and hence both peak current and peak instantaneous power to be dissipated.  Perhaps adapting part of the quick-clamping circuitry from a (cheap) surge protector would be a valid starting point.

[richg1998]

Bis

This is probably a dumb question, but I just got a Circuitron Snapper and want to be certain I am hooking it up correctly to my Atles snap switches. I presume I cut to 2 leads going  from the power supply to the switch buttons, then  attach the out put side of power supply to the input side of the Snapper. Then attach the 2 wires from the switch buttons to the output side of the Snapper.

 I just want  to be certain, before I destroy the switches.

 Thanks for  your inputs.  

 

Just follow the instructions that come with it. Many use it with no issues.

I made my own.

Rich

[BroadwayLion]

LION did that once. Burned it out. End of Story.

 

ROARING

[Bis]

Thanks for the prompt replys everyone. I'll look for some 18 AWG and get to it after my "honey do s " are done.

Ken

[BigDaddy]

I don't understand the email notification.  I am getting them for caboose interiors and I don't think I ever clicked on that thread. 

Your reasoning was correct.  You want the Snapper to do something when you push the button, so it has to be fully charged.  The pdf file above mentions specific wire gauges to be used.

 

 

[Bis]

Yes that is the Snapper that I have. Sorry it took so long to reply, I  thought I would have gotten an email to let me know someone had replied.

Ken

[mbinsewi]

Is this what you have? 

http://www.circuitron.com/index_files/ins/800-5303ins.pdf

Mike.

[Bis]

This is probably a dumb question, but I just got a Circuitron Snapper and want to be certain I am hooking it up correctly to my Atles snap switches. I presume I cut to 2 leads going  from the power supply to the switch buttons, then  attach the out put side of power supply to the input side of the Snapper. Then attach the 2 wires from the switch buttons to the output side of the Snapper.

 I just want  to be certain, before I destroy the switches.

 Thanks for  your inputs.