Hi,
I have 4 Hoffmann switch machines and want to use a NCE switch 8 and Larry at NCE said it used two wires to the machine and the Hoffmann machine uses three wires. Any person out there have any experience with Hoffmann machines and DCC? I use both NCE and Digitrax DCC systems on my layout by the way.
Thanks,
Barry
I found this site with a diagram and some descriptive text.
http://finneyandsmith.co.uk/finneyandsmith/hoffman.html
From the description, this is neither a twin-coil nor a stall motor device. I don't think you're going to find a stationary decoder for it.
It takes an iron man to play with a toy iron horse.
Mister Beasley,
That is the switch machine I have and I have come to the conclusion that I may not be able to use a stationary decoder with it. Maybe someone has figured out how to do it and will see this post and help me out.. I can only hope.
Based on the wiring diagrams, since it appears that for AC power the two diodes go opposite each other, it may be possible to tie those two ries together, and combined witht he common, operate them by reversing the DC polarity, like a Tortoise. What I haven't been able to find is a spec on how much current it draws.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy,
Rated for 24V, 4A.
You could run them with an Aux-Box.
http://factorydirecttrains.com/aux-boxdccappliance.aspx
An Aux-Box is a set of DCC-controllable toggle switches. It would take a pair of Aux-Box contacts to run one Hoffmann, though. This would bring the cost of DCC control to about $30 per turnout, so it would be cheaper to use Tortoises and a Switch 8.
rrinker What I haven't been able to find is a spec on how much current it draws.
The diagram I linked above suggests 16VAC, 1A. These do not appear to be stall motors, as they mention a built-in switch. I've got a Switch-it (2 Tortoises) and from the speed it runs I would say it's putting out 9 or 10 volts. The Switch-it, which draws its power from the track, may not put out a high enough voltage to run the Hoffmann. Besides that, the Switch-it output is DC.
I wrote an email to Finney & Smith Co. about a half hour ago and received a response from Dave Finney a few minutes ago and he explained that he is no DCC expert and that he will be find out if in fact the machine can be used with DCC. Wow, that was a fast response and I guess I shall wait to hear from him. Hopefully it will be positive and that I will be able to report back on this. Yes, and using some of the things suggested get kinda expensive. Right now my Hoffmanns are hooked up to a cheap Bachmann transformer and a DPDT, just would be nice to use a stationary decoder and my DCC throttle to throw the turnouts.
Hopefully maybe somebody has experienced this.
The Lenz LS150(as well as the relabeled Atlas version) should work fine with those switch machines. It outputs AC at 3 amps for 1 sec , or 1 amp for longer than 1 second.
Another option is to use a stationary decoder to trigger a relay(for example, an Atlas snap relay) and have the relay control the turnouts.
The 24V 4A is the rating of the contacts for frog power.
I suspect they probably draw too much current for a Switch-It. They might work with a DS64. I found other links which mentioned that 9-12V is fine for them and they will run. Yes they take AC, but the wiring digram says you need the AC plus two diodes, one on each of the control wires - and the diodes go the opposite way, that's why I suspect they can workw ith DC if you tie those two wires together and reverse the polarity ala Tortoise. That is in effect what you are doing with the AC plus pair of diodes. I saw this on a thread in a different message board where a user has about 5 different types of stationary decoders and was trying to figure out which might work with the Hoffman motors.
Since they have cutout contacts, they would work best with a system that puts continuous power to the motor. Another one that surely has enough power, IF they can indeed workj with DC, is the Lenz LS150. The only issue with those is that if you extend the pulse time to allow the machine to operate all the way until it cuts off, the LS150 will not respond to any other switch commands during this time. Discovered this trying to use them on a friend's layout.
Finally, if it's small space you want, I suggest Tam Valley servos and controllers. Even smaller than the Hoffman motors, and there are a wide variety of control options, bor DCC and for local fascia controls. Also cheaper than Tortoises.
OK all,
I received a reply from Dave Finney and here is his answer..........................
I friend suggests, connect the two outer terminals together and to one input. Connect the centre terminal to the other input.
Dave
Those you that have made some post might you have any thoughts to his answer?
I have looked at purchasing the Tam Valley servo kits and I have a friend that has installed a number of them that I need to travel to his place and check them out.
Thanks for that suggestion.
I'd test the Hoffman with something like a 9V battery before hooking one to a Switch8. If it works try with a meter set on amps in series. It should be too low to read, if so try the max milliamps setting (the cheapy Harbor Freight meter has a 200ma range - it's fuse protected so if it ends up being over this, all it will do is blow the fuse which can be replaced). You want to know what kind of current these Hoffman motors draw, because the Switch8 has a very limited output. Fine for the intended purpose of running a Tortoise, since they only draw 15ma, but if the Hoffman draws more like 150ma, it will not be good for the Switch8.
rrinker...They might work with a DS64...
I doubt they will work with a DS64. The wiring diagram calls for a 16v, 1.0 amp power supply. I could not find a rating for the DS64's outputs, but if the switch machine really draws close to 1 amp, then I doubt the DS64 can supply that much.
rrinker ...Another one that surely has enough power, IF they can indeed workj with DC, is the Lenz LS150. The only issue with those is that if you extend the pulse time to allow the machine to operate all the way until it cuts off, the LS150 will not respond to any other switch commands during this time...
...Another one that surely has enough power, IF they can indeed workj with DC, is the Lenz LS150. The only issue with those is that if you extend the pulse time to allow the machine to operate all the way until it cuts off, the LS150 will not respond to any other switch commands during this time...
The reason I suggested the LS150 is because it has AC outputs, so it should work regardless of the internal wiring of the switch machine(no need for it to work with DC). The wiring would be straight forward - red in the wiring diagram to C on the LS150, one brown to '+' and the other brown to '-'. The delay in receiving commands definitely could be an issue, however, especially if you intend to use routes.
draftingplans ... I friend suggests, connect the two outer terminals together and to one input. Connect the centre terminal to the other input...
...
I friend suggests, connect the two outer terminals together and to one input. Connect the centre terminal to the other input...
This seems to confirm what Randy said about the control of the turnout. Here is how I believe it to be wired: The red wire gose to one terminal on the motor. Both of the brown wires go to the other terminal, but each one goes through a diode, with the diodes in opposite directions. By applying AC to the red wire and one brown wire, the diode only allows the current to flow in one direction. By switching the brown wire, you switch which direction the current flows. By connecting the two brown wires to each other, you can apply DC to the red wire and pair of brown wires and control the direction of the motor by switching the DC polarity. By doing this, you control the tunrout the same way that you would a Tortoise, however, these appear to draw much more current than a Tortoise.
I would do as Randy suggest and test their current draw. If they are less than 50 ma, then the Switch-8, wired as described above, should work(the Switch-8 outputs are rated for 50ma). If they draw more than 50ma then you'll need someting else.
If the Switch-8 won't work, probably the easiest solution is the LS150 or a decoder that can drive a dual solenoid turnout driving an Atlas snap relay(or equivalent) with the contacts of the relay controlling the tunrout.
If that tiny little motor in that thing draws nearly 1 amp, then I'd seriously consider tossing them, that's insane. Just because they recommend feeding them with a 16V 1 amp supply doesn't mean each one draws that much.
That's why I'm not a big fan of those Cobalt motors either, great, some improvements on the Tortoise, but then you went and gave it more than double the current draw. Why? I thought we finally left behind the days of heavy switch motors that have current draws measured in amps.
Randy and others,
I am leaning towards dumping the Hoffmanns and order a number of the Tam Valley units as they will probably mount easier than Tortoise machines for me. I will head to see my friends Tam Valley units as soon as we quit having April snow storms. Got 12.5" of snow the last two days. Not fun!!!!!
I highly doubt that the Hoffmanns actually draw close to 1 amp, but even if they draw 0.1 amps, that's too much for the Switch-8.