Comments on: How to Wire Reed Switches

By: Graham Norris

Graham Norris — Tue, 10 Jul 2018 07:18:17 +0000

I cut two 3mm brass tubes about 30mm long and soldered a length of wire into one end of the tube. Drill a 3mm hole between the sleepers 3 spaces between holes. insert the brass tubes and tap down just below the sleepers. bend the wire of the reed switch ond insert into each brass tube. I then cut a small piece of cocktail stick and fitted it into the hole this makes a good contact with the reed switch wire. This can be painted black (if the reed switch should fail it can be changed very quick)

By: joe gennuso

joe gennuso — Sun, 18 Feb 2018 19:11:50 +0000

I have a HO train layout with two turnouts when I put a third turnout in the train will not run the turnouts are run manually no wires.

By: Tom

Tom — Tue, 08 Dec 2015 17:02:51 +0000

I have bent the connectors down toward the HO track (center of track) and soldered wires to them and run the wires through a hole between rail ties for electrical connection below the platform. I glued the magnets to caboose as to add weight to these lighter cars and for resetting the block behind to avoid collisions (just in case of derailment).

By: Chuck Davis

Chuck Davis — Wed, 18 Nov 2015 22:40:37 +0000

I use these a lot on my n-scale layout. Place them between the rails, parallel to the rails – you should remove a tie or two so the switch can sit flush with the ballast. You can bend the leads downward and solder on a short length of light hookup wire to the ends. When bending, hold the lead with a needle-nose pliers at the edge of the glass, then bend on the opposite side of the pliers, away from the glass – this minimizes stress on the device. Glue a small size (1/4 inch or less dia) high-powered neodymium magnet to the bottom of a locomotive to trip the switch. I use these to stage trains in hidden areas, by pulling the train forward until the switch is tripped, lighting an indicator on a panel.

By: Frank B

Frank B — Wed, 18 Nov 2015 18:03:09 +0000

Please may I correct a technical error in the original post ?

The contacts in a reed switch do not have “magnetic poles”. The contacts are not magnets themselves, but are paramagnetic. They only become magnetic when an external magnetic field is applied, and only then attract each other and close the switch.

(If the contacts were permanent magnets, the switch would be permanently closed.)

The diagram shows the contacts as being magnetic monopoles. According to Wikipedia:
“There is no conclusive experimental evidence that magnetic monopoles exist at all in our universe.”

By: Kevin

Kevin — Wed, 18 Nov 2015 06:11:23 +0000

I have used these on my layout to operate crossing signals I routed out a space that would hold the reed switch and I soldered the wires to the leads of the reed switches. the reeds control a series of relays that operate the flashing crossing lights. I put heat shrink tubing over the soldered joints. A word of warning do not bend the leads from the switches as this can break the glass tubing of the switch. A small powerful magnet glued to the bottom of the loco operates the switch. as the engine passes over the reed switch a self latching relay start the lights flashing and a second reed switch operates a second relay unlatching the first relay that stops the lights flashing. a second set of reed switches operates the lights of a train running in the opposite direction.

By: David Broad

David Broad — Wed, 18 Nov 2015 04:43:03 +0000

You can also get change over reed switches which act as SPDT switches and can be used in a break when magnet present mode.

By: Adrian

Adrian — Wed, 18 Nov 2015 01:16:45 +0000

I would use the small “Female” connector pins used in “MOLEX” connectors if glue mounted switch.
Less strain than soldering to them.

By: Dennis

Dennis — Wed, 18 Nov 2015 00:44:08 +0000

Wiring up that reed switch would be the same as wiring up a SPST switch.

It’s just on and off for a single circuit. No bigger.