Running Lionel Gateman off of a DC transformer?

The solenoid will draw a lot more current with DC than AC at the same voltage.  I've not tried it, so I don't know how it will react.

The Instructions say to use 14VAC and not to use 18VDC to activate this accessory:

@SteveH posted:

The Instructions say to use 14VAC and not to use DC to activate this accessory:

For the reason I stated Steve.

@gunrunnerjohn agreed.  I started my reply before your reply posted.

@Mannyrock posted:

Will the solenoid of the gateman operate OK on a DC circuit?  Or is this likely to burn it out.

You can use low voltage DC, adjustable to the lowest it will operate on satisfactorily would be the best.  You can check the current draw on 14v AC, and then just don't exceed that current with DC to see if you are in range.

Thanks,

My plan would be to use the posts on the DC transformer that are governed by the throttle, and just turn the throttle up half way or so, or the lowest setting that would operate the gateman..

I currently have a really small DC transformer with throttle, that came in a starter set for an N Gauge train.  I paid $5.00 for it at the flea market.  With the throttle turned up one-third of the way,  the Atlas Oil Pump operates at a nice slow realistic clip.

Mannyrock

Simply put, AC coils ran on DC will quickly overheat and melt things. Listen to @SteveH, @gunrunnerjohn and the actual freakin MANUFACTUERS MANUAL and not what you wish to hear.

To add to the discouragement above re the use of DC power on a solenoid-operated accessory...

IMHO, the problem of overheating will first deteriorate the enamel coating on the solenoid coils.  As shorting begins, it will accelerate/exacerbate the heating of the coil.  Sure, anything plastic within range of the coil will deform.  I've seen plenty of overheated coils in disassembly of pre/post war solenoids.  Not a pretty sight, not an easy fix.

BTW...can you be sure that 1) you will never run a train too long or too slow in activating this accessory, thereby avoiding overheating at ANY DC voltage setting?, and 2) can you be sure a train will never be stopped with this accessory activated, thereby guaranteeing overheating?

IOW, I'm with Steve and GRJ...do NOT venture into the DC realm on this accessory.

Just sayin'...

KD

As kind of an off shoot: sounds like the same thing would apply to the reverse unit in a Gilbert engine, if run on DC...?

Mark in Oregon

@Strummer, we have hashed AC and DC with you many times including your reverse unit specifically: https://ogrforum.ogaugerr.com/...2#157829273395498932

You are, of course, correct. My apologies. 👍

Mark in Oregon 🎄

OK Guys, thanks for the additional info.

Looks like I'll run the Gateman off of the fixed AC voltage posts of my old 1033 transformer, that is currently not in use.

In my HO days, half a century ago, I burned out a lot of solenoids, even when I had them properly hooked up and powered.  So, I am always "concerned" about solenoids.

Mannyrock

Out of curiosity, is the reason you want to run it off DC because of the buzzing associated with spring-loaded solenoid accessories?  Some guys like the "play action" effect of the buzzing - others find it less endearing.

Separately, has anyone actually measured the gateman solenoid electrical parameters?

The 18V DC warning in the instructions reminds us that there might be layouts that only have DC for track power.  For example this might be someone who is getting into the hobby via a Lionchief set with the fixed-voltage DC power pack.  Or how about guys messing with DC battery-powered "dead-rail" layouts.

Sure, you can get a used AC-output transformer for next to nothing at a train show or wherever.  But there are far more options for modern, lightweight, compact DC-output power packs that surely have the beef to drive a solenoid-activated accessory.

OGR being a discussion forum that is....

To prevent damage, you could use a PTC on the gateman so that if the power lingers too long, it would be shut off by the PTC.

And here all along I thought that buzzing solenoids, the smell of ozone mingled with "la odeur de pellet", dozens of green and red lights, bells, whistles and horns, steel-on-steel rushing sounds, chuffing sounds, logs rolling, plastic coal rattling, barrels clattering....giggling  little kids, oohing and ahhing big kids, barking dogs, Bing Crosby crooning in the background...all part of the Lionel/O3R shticky ambiance du jour.

Silly me.

@stan2004 posted:

The 18V DC warning in the instructions reminds us that there might be layouts that only have DC for track power.  For example this might be someone who is getting into the hobby via a Lionchief set with the fixed-voltage DC power pack.  Or how about guys messing with DC battery-powered "dead-rail" layouts.

First off, 3 rail O gauge has over a century of AC on the rails. Essentially everything will run that way. Some of the LionChief family Ready to Run sets come with the less capable small cost reduced DC power supplies which go against the grain of over century of tradition and compatibility. Fortunately all LionChief equipment can run on AC power. Current wisdom is to grow up in to AC world and retire the DC wall wart. Those very very few who choose to deviate their setups for whatever reason must be up to the task of re-engineering (and actually enjoy that aspect of it!). For the most of us, common ground AC operation and accessory activation is spot on.

@stan2004 posted:

Sure, you can get a used AC-output transformer for next to nothing at a train show or wherever.  But there are far more options for modern, lightweight, compact DC-output power packs that surely have the beef to drive a solenoid-activated accessory.

This isn't about the "power capacity" of the power supply, but that the characteristics of the coil (current draw, impedance, resistance et. al.) were geared towards the AC environment. When applying DC to such a solenoid, one generates much more heat which obviously is detrimental. This leads to one needing to re-engineer the solenoid and/or power feed for what gains when @Mannyrock stated he is in an AC world.

@stan2004 posted:

Out of curiosity, is the reason you want to run it off DC

Right from the horses mouth:

@Mannyrock posted:

Will the solenoid of the gateman operate OK on a DC circuit?  Or is this likely to burn it out.

My Atlas oil pump is rated to run off of either DC or AC, so that's why I am wondering about the gateman.

As stated, wisdom states DC operation is off the table. As for the Atlas product, it has its own onboard power regulator that can deal with the AC or DC input and translate it to an appropriate level for the internal motor. This is evident in Eric's review around the 3:30 mark where the underside is shown:

Plus, the "gateman" works on a temporary shot of juice, whereas the oil pump thing is simply a motor that runs...right?

Mark in Oregon

@gunrunnerjohn posted:

To prevent damage, you could use a PTC on the gateman so that if the power lingers too long, it would be shut off by the PTC.

Exactly.

OGR being a discussion forum, I think it worthwhile to discuss the topic.  The instructions state the gateman works best with 12-14V AC.  In other words, it essentially assumes you have a train transformer with traditional Auxiliary/Accessory AC output separate from variable AC track voltage.  But what if entering the hobby via 18V AC command control with fixed-output AC bricks that don't have a 12-14V AC output?  There have been many threads asking how to reduce the 18V AC from a fixed-output brick to a lower AC voltage for use with accessories.  The stock answer is to re-purpose a spare AC transformer bought some time in the last century.  A common question is to inquire whether the accessory operates off DC.  Many accessories operate just fine on DC.  Manuals don't even mention DC not because they can't or won't operate on DC, but because they were built in the last century when low-voltage regulated DC power supplies were expensive - requiring solid-state electronic components like transistors that were quite the novelty.   Much easier to use AC since it only requires fiddling with the windings of a transformer and no expensive electronic parts. 

I'm curious if anyone has actually measured the gateman solenoid's electrical parameters. While the instructions say not to use 18V DC, it does not explicitly say it does not work on DC.  Obviously, the 18V DC reference is because of the LionChief low-power DC wall-wart.  How much AC current does it draw at 14V AC?  What is the Ohms/resistance of the coil?

The magnetic field or pulling power of the solenoid coil is proportional to the current flowing at the time.  It does not matter if the applied voltage is AC or DC.  That the current in the coil is smaller for 18V AC vs. 18V DC is a separate matter.  Obviously some coil accessories depend on the alternating magnetic field to buzz or vibrate the accessory to operate.  I would be interested in hearing someone who has damaged their solenoid plunger by  magnetizing because they used DC.

@stan2004 posted:

I'm curious if anyone has actually measured the gateman solenoid's electrical parameters. While the instructions say not to use 18V DC, it does not explicitly say it does not work on DC.  ...How much AC current does it draw at 14V AC?  What is the Ohms/resistance of the coil?

Yes - see J L Cowen's Postwar Lionel Trains O-Gauge Reference Manual II for Motorized Units, Rolling Stock & Accessories by Robert Hannon, specifically section 5-5.

@stan2004 posted:

I would be interested in hearing someone who has damaged their solenoid plunger by  magnetizing because they used DC.

I demagnetize them all the time with either running them on AC or something like a screwdriver (de)magnetizer.

@Mannyrock posted:

Will the solenoid of the gateman operate OK on a DC circuit?  Or is this likely to burn it out.

What's the catalog number?

Two weeks ago I tried variable DC on a modern gateman, lasted about 30 minutes before it melted some insulation in the coil and shorted out.  I had it adjusted as low as I could and still get the gateman to come out reliably.  It had a duty cycle on an oval under the Christmas tree of about 10seconds on, 10 seconds off.  So I wouldn't recommend it.

That said, 20 years ago I ran the old solenoid Lionel crossing gates on DC with no issues.  Perhaps there is something different in how the new v. old solenoids were manufactured.

@Burl posted:

Two weeks ago I tried variable DC on a modern gateman, lasted about 30 minutes before it melted some insulation in the coil and shorted out.  I had it adjusted as low as I could and still get the gateman to come out reliably.  It had a duty cycle on an oval under the Christmas tree of about 10seconds on, 10 seconds off.  So I wouldn't recommend it.

That said, 20 years ago I ran the old solenoid Lionel crossing gates on DC with no issues.  Perhaps there is something different in how the new v. old solenoids were manufactured.

OK now we have a real after-action report!   Thanks for chiming in.

Did you happen to measure or recall how many Volts (DC) got the gateman to come out reliably?

Why did you (attempt to) use DC in the first place?

@Burl posted:

...That said, 20 years ago I ran the old solenoid Lionel crossing gates on DC with no issues.  Perhaps there is something different in how the new v. old solenoids were manufactured.

That's why I'm asking for the number... the new ones melt down too readily already on AC. They are very cheaply made. A 45 or 45N, or 145, work just fine on low voltage DC.

@ADCX Rob posted:

That's why I'm asking for the number... the new ones melt down too readily already on AC. They are very cheaply made. A 45 or 45N, or 145, work just fine on low voltage DC.

The 73-6998-250 manual that SteveH linked to above suggests a publication date of 2013 which I suppose is a "modern" version.

I'm still curious why it specifically warns against 18V DC as opposed to saying don't use DC period.

@ADCX Rob posted:

That's why I'm asking for the number... the new ones melt down too readily already on AC. They are very cheaply made. A 45 or 45N, or 145, work just fine on low voltage DC.

Rob, just to be clear, are you saying the modern ones melt even running on AC voltage?  Do you have any more info on voltage levels or whatever?  The "manual" makes no warning against operating at 18V AC for example, warning about continuous operation or duty-cycle limits, etc.

@stan2004 posted:

Exactly.

I'm curious if anyone has actually measured the gateman solenoid's electrical parameters. While the instructions say not to use 18V DC, it does not explicitly say it does not work on DC.  Obviously, the 18V DC reference is because of the LionChief low-power DC wall-wart.  How much AC current does it draw at 14V AC?  What is the Ohms/resistance of the coil?

I don't know why the format of this is messed up, but here goes-

At 60Hz, my PW 145 measures-

7.64 + 2.64j ohms with the core out of the coil (man in shed)

7.64 + 7.92j ohms with the core in the coil (man outside)

DCR is about 7.5 ohms

It’s hard to get accurate current readings, the resistance goes up rapidly as the coil heats up. But at 14  volts DC, the current is about 1.9A, at 14 volts AC the current is about 1.3A.

So-

At 14 volts AC, the coil dissipates about 1.3**2 x 7.64 = 13 watts

At 14 volts DC, the coil dissipates 14**2/7.5 = 26 watts.

But-

Raising the DC voltage to 18 volts DC (what the OP’s instruction sheet warns against) gives a coil dissipation of 18**2/7.5 or 43 watts!

Now-

If the DC voltage is lowered to about 9.9 volts DC the coil dissipates 13 watts, the same as the 14 volt AC value. The action of the man is significantly less snappy though; on AC the current is higher when the man is in the shed, due to the lower reactance of the coil (hence higher current) when the core is out of the coil. But there are no reactive effects at DC, so the coil current remains constant regardless of the position of the core.

Obviously, the coil in the modern gateman may be different, but I suspect that the basic situation is the same, unless there are some electronics involved with the coil.

@stan2004 posted:

Rob, just to be clear, are you saying the modern ones melt even running on AC voltage?  Do you have any more info on voltage levels or whatever?  The "manual" makes no warning against operating at 18V AC for example, warning about continuous operation or duty-cycle limits, etc.

I believe "Modern" in this case means anything from within the past 4 or so decades as opposed to the good ol' hardy ones of the 4 more preceding decades.

I'd say that old v. new definition is about right.  My "old" gateman and crossing gates were 60's vintage as I recall.  Might have been one mid-70's crossing gate.

It was around 14v DC to get the gateman to reliably pop out.

The really really new gateman releases have a DC solenoid with the following electronic driver board which takes AC or DC input (note the discrete diode  full bridge rectifier):

@PLCProf posted:

Wow.  That's great stuff!  Thanks for providing the info.

So the Lionel parts diagram for the 145 suggests you can't get the coil anymore.  But for discussion purposes, it seems to me if the question is how to make the gateman operate on DC, I'd consider some major surgery to replace the coil-plunger-spring mechanism with a $5 geared-DC motor to drive the gears (parts 10 and 15 in the diagram).  Yes, this would require some new (but not complicated) electronics but the power usage would go way down.  This would be like how modern FasTrack switches use a fraction of a revolution of a geared DC motor rather than power-hungry solenoid plungers.

Or.  To use the existing solenoid mechanism, I'm imagining a DC circuit similar in concept to DC capacitive discharge circuits that drive solenoid plungers in turnouts.  That is, since the gateman operating at a "safe" 9.9 Volts is not snappy enough, then some kind of energy storage (e.g., capacitor) that provides a momentary burst of power when the gateman is first activated to fling him out the door with the attendant worker's comp claim for whiplash.

It's clever how the lower impedance when the man is in the shed provides a boost in the starting current to fling him out the door.  Then the current and hence the pulling forces on the spring drops as the impedance rises with the plunger in the coil.  It's interesting that the current in the active position drops which occurs when the spring is extended (if I understand how this thing works) which is when the return force on the spring is greatest...since the force in a spring is proportional to the extension.  Seems counter-intuitive.

I can see how 43 Watts at 18V DC would be a problem when nominally 13 Watts at 14V AC.  But you'd think there'd be a warning about using 18V AC too...since that would be almost 22 Watts which also seems like a lot of heat for an arguably small space.

@stan2004 posted:

I can see how 43 Watts at 18V DC would be a problem when nominally 13 Watts at 14V AC.  But you'd think there'd be a warning about using 18V AC too...since that would be almost 22 Watts which also seems like a lot of heat for an arguably small space.

I think the warning is directed specifically to the people who use the 18 VDC supply furnished with the low-end LionChief starter sets.

I'm guessing 43 watts would cook the coil in seconds!  OTOH, the little set transformer probably would either bog down or blow up with that kind of load.

@PLCProf posted:

I think the warning is directed specifically to the people who use the 18 VDC supply furnished with the low-end LionChief starter sets.

Makes sense.  But I'm imagining someone new-to-the-hobby graduating from the 18V DC supply directly to a 18V AC fixed-output brick for command control ... never experiencing conventional control much less having a variable AC throttle-type transformer with fixed 14V AC accessory output.

For what it's worth I've operated the p/w 145 gateman and semaphores  using bridge rectifiers to convert from ac to dc for several years with no issues. I tried the same on the 445 switch tower but it needs the vibration from ac to get the man down the steps!

@stan2004 posted:

Rob, just to be clear, are you saying the modern ones melt even running on AC voltage?

The chinese coils run very hot with AC on what would seem to be ordinary duty cycles.

I also have had no issues with prewar-postwar coils in accessories and with e-units run on DC. I have a test bed MPC diesel at over 25 years running on DC to the e-unit coil and it still works perfectly.

The Gateman I have is from the mid-1960s, with a Toys-R-Us tag on it.

I guess I could tap the power for it off of my track transformer, a Z-1000, but that transformer does not put out alot of juice, and its already powering 12 Lionel 022 switches and lanterns.  :-O

So, I am going to use a separate transformer.   Since my Atlas Oil pump, and several of my accessory lights, can run off of DC, and since I already have a small DC transformer, that is why I asked about using DC.

Cheap Lionel starter-set AC train transformers with throttles are indeed a dime a dozen at the flea market (well, more like $6.00), so if I have to buy one of those and set the throttle to the lowest setting that will make the gateman mechanism continue to work, that would be no problem.  I now have a dedicated 20amp outlet for my layout, so I would imagine I have the juice to run many smaller transformers at once.

I was just trying not to add another AC transformer.

Thanks

Mannyrock

@Mannyrock posted:

I was just trying not to add another AC transformer.

Now you see why so many like the larger transformers with multiple variable outputs!

@Mannyrock posted:

I now have a dedicated 20amp outlet for my layout, so I would imagine I have the juice to run many smaller transformers at once.

Or eight fully loaded ZWs.