CD power supply for twin-coil switch machines (NJ, Tenshodo, etc.)

[fwright]

cacole

 I don't know a source, but for that many machines thrown simultaneously you'll need a supply with a current output of around 10 Amps or more.  The old NJ International and Tenshodo machines each draw 2 or 3 Amps to throw, and if the power supply can't handle that much load they won't throw.

Cacole

You are right if we talking about the rating of a standard power supply.  A CD unit stores large amounts of energy in the capacitor(s).  When the button is pushed, a jolt of energy is delivered to the switch machines that quickly tapers off to nothing as the charge on the capacitor(s) is discharged.  The more switch machines in parallel, the quicker the capacitors are discharged.  The jolt allows the machines the energy to throw, and by then the current is tapering down, avoiding switch machine burnout.

The number of switch machines to be thrown simultaneously controls the size of the capacitor(s) needed in the CD unit.  The size of the capacitors, along with the power supply, determines the recharge time for the capacitors.  In typical mr fashion, most CD units have considerably more capacitance than is needed to throw a single machine - usually approaching overkill - on the basis that you never know when you will want to throw 10 switch machines simultaneously.  Circuitron does rate their unit for 10 switch machines.  Most of the published circuits will easily handle 2-3 switch machines.  And if that's not enough, you simply add a second capacitor (same size) in parallel.  This doubles the number of switch machines that can throw simultaneously while doubling the recharge time (typically anywhere from 1/2 to 2 seconds).

The other beauty of the CD unit is that a 1 amp rating on the recharge power supply is usually more than adequate - where it wouldn't be nearly good enough to throw 2 switch machines, much less 5, on its own.

If you are going to use more than a few twin coil switch machines on your layout, a CD unit is a wise investment to protect switch machines and controls (buttons).  If you want to throw more than 1 switch machine at a time, a CD is pretty much a necessity unless you have 5 amp power supplies lying around.

hope this helps

Fred W

[cacole]

 I don't know a source, but for that many machines thrown simultaneously you'll need a supply with a current output of around 10 Amps or more.  The old NJ International and Tenshodo machines each draw 2 or 3 Amps to throw, and if the power supply can't handle that much load they won't throw.

[richg1998]

I forgot about Circuitron. The device is called the Snapper. Walther's does not show it in stock.

Try searching with Google for circuitron snapper.You might find someone who stocks it.

Below is a link to the Circuitron site. Lots of good stuff if you do not like build circuits

http://www.circuitron.com/index_files/catalog.htm

 

 

[fwright]

TucsonTom

Is anyone aware of an out-of-the-box CD power unit/supply with quick recharge and capacity to throw 4 to 5 twin-coil switch machines such as the NJ, Tenshodo type?

TucsonTom

 

Circuitron makes the CD unit you are looking for.  Walters had it in earlier catalogs; I don't have the 2010 catalog to check.  You don't have to worry about identical switch machines - differing current draws are not an issue.

A CD unit is very simple to build (15-30 minutes depending on experience) and costs less than $10 for components.  It's a good 1st  electronics project.

my thoughts, your choices

Fred W

[richg1998]

You might find a ready to use one in the below. Link.

http://www.google.com/search?hl=en&q=model+railroad+twin+coil+supply&btnG=Search&aq=f&oq=&aqi=

Rich

[nedthomas]

To operate 4 or 5 twin-coil machines in parallel from one control button they should be:

1:  The same make and have the same electrical characteristics. That way the current should divide equal between the units.

2:  Should be the same mechancially i.e. the linkage, thrown rod and etc. must be equal on all units. Any unit that hangs up mechancialy will "steal" most of the current and prevent the others from throwing.

[TucsonTom]

Is anyone aware of an out-of-the-box CD power unit/supply with quick recharge and capacity to throw 4 to 5 twin-coil switch machines such as the NJ, Tenshodo type?

TucsonTom