I'm getting ready to wire my new freight yard lift bridge, and I'm looking for some spring contacts to carry power across without screwing around with connectors.
Specifically, I'm thinking that the ledge that the bridge sits on will have some spring loaded contacts projecting up, and bridge will have a flat copper surface that makes contact with them when the bridge is down.
I'm just looking for some ideas on some reliable contacts that I can press into service for this job.
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What about magnetic contact switches used in door or window security? or perhaps making use of a reed switch.
@SLQ32 posted:What about magnetic contact switches used in door or window security? or perhaps making use of a reed switch.
Uhh... you're missing the point, the object of the exercise is to carry power, not provide an isolated switch function. 
@Dennis-LaRock posted:
I have a couple styles similar to that on order now, I went to Amazon for quick shipping in case I don't like them and want to do something else.
Ohh ok i miss understood it then
I feel like this is a trick question when it come from GRJ! Shoot, he has forgotten more than most know about contacts, springs, etc. But how about a limit switch or two? Just an idea. Our club used them on the entry module that was hinged. The below item won't do what you want directly but they are pretty reliable. Train ON!
You're making the same mistake as previous posters, the object of the exercise is to carry power across the gap. I'm not worried about power when the bridge is up, I just want something to connect when it's down so I don't have to manually plug/unplug connectors.
Simple, Durable and Reliable... John: "Oh, you will get it done Dennis... beware the carnage in your wake" 
You now have me designing a lift bridge so that my layout is at least bigger than your yard John!
How about homemade: nails, countersunk and free floating, sprung with discarded claw springs. Countersink the nail heads so that they come in contact with your copper sheet or studs located on the underside of the bridge bent without causing misalignment of the track surfaces when the bridge is lowered. Cheap, easy and Bezos doesn't get a dime.
P.S. Spent .38 brass with primer pocket drilled out would make a nice housing to ensure proper spring alignment. I'll bet you've got some of that on hand, too.
My deep fryer has a magnetic connector so that the cord will disconnect should the fryer be dropped or moved too quickly. It works very well and the cords are readily available but I am not sure where to get the mating piece that is a part of the fryer. These work quite well because the magnet hold tight allowing a very good electrical connection.
Actually, I just checked my Tfal cord and the cord portion is magnetized so it could work with a plated steel mate.
As someone who frequents thrift stores and yard sales, I may start looking for some inexpensive used fryers to remove these parts from .
Good luck in your search,
Don
@Bogart posted:I feel like this is a trick question when it come from GRJ! Shoot, he has forgotten more than most know about contacts, springs, etc. But how about a limit switch or two? Just an idea. Our club used them on the entry module that was hinged. The below item won't do what you want directly but they are pretty reliable. Train ON!
I think Bogart is on to it, right?!! Thanks for providing a link. The photo here is what I used on my last layout (just like in that link) and a set of these worked great for 7 years before I dismantled it. I bought them at Radio Shack -- so I need a new source. I got this idea from Jim Barrett's Backshop column years ago and had the opportunity to thank him in person at Trainfest for the idea. I wish I had save the Run # of that column. Prior to that I crashed an engine.
I love the idea of the magnetic cord for a deep fryer. That could be useful for a lot of things. The nice thing about the spring contact switch, however, is it always cuts power on the bridge and the track leading up to it when you lift the bridge -- so no plug in required.
Mike
I have some of the pogo pins coming in a couple of styles. I'm hoping they'll be suitable. They really want to be spring loaded so as not to affect the bridge seating, any fixed contact is going to end up being problematic.
I'll see how the pins I have coming work out... 
@IRON HORSE posted:
I bought them at Radio Shack -- so I need a new source.
See my post from yesterday:
Radio Shack | Mellow Hudson Mike
Mike
@IRON HORSE posted:
I think Bogart is on to it, right?!! Thanks for providing a link. The photo here is what I used on my last layout (just like in that link) and a set of these worked great for 7 years before I dismantled it. I bought them at Radio Shack -- so I need a new source. I got this idea from Jim Barrett's Backshop column years ago and had the opportunity to thank him in person at Trainfest for the idea. I wish I had save the Run # of that column. Prior to that I crashed an engine.
I love the idea of the magnetic cord for a deep fryer. That could be useful for a lot of things. The nice thing about the spring contact switch, however, is it always cuts power on the bridge and the track leading up to it when you lift the bridge -- so no plug in required.
Mike
These are available from Amazon: less than $7 for a dozen of them, much cheaper than Radio Shack.
Starter solenoids use large copper contacts. Check a repair shop’s junk pile. Heavy duty whisker switches might also work. We use them on milk lines to insure they are hooked up right, such as disabling the wash system if they are still connected to the milk tank.
Spring contacts and pads from old converted proto-one locomotives?
@Chuck Sartor posted:Spring contacts and pads from old converted proto-one locomotives?
I thought of that Chuck, and I have a bunch of them, but carrying 10 amps is probably out of their ballpark.
@Bob posted:These are available from Amazon: less than $7 for a dozen of them, much cheaper than Radio Shack.
And have absolutely nothing to do with what I need! 
John: Maybe something like this would work. Most have never been painted. 
copper nail with a spring.... installed in pocket hole
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