# A silly AC and DC question



## JMedwick (Feb 11, 2017)

A noob question. I have seen some Atlantics listed with AC after the numbers (like the 300AC) and some Northern’s with DC after the numbers (like the 334DC). I get that those stand for alternating vs direct current, but why is the type of current called out on some af trains but not others, or more accurately, did Gilbert make three types of engines (AC only, DC only, and those that can take either)? I though, perhaps mistakenly, that all AF trains were made to run on AC. I get that you need a rectiformer to run a DC train. Do you need anything special to run the AC only trains?


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## mopac (Feb 24, 2011)

Many (most) Af locos will run on either. But if it is specified like AC or DC that is
what is needed to run the loco. AF and lionel transformers put out AC so nothing else
needed to run AC engines. AF made rectifiers that used to run DC locos. cramden or
flyernut will give you a better answer. I read somewhere why AF made DC locos, but
I can not remember the reason. I have 2 302AC locos.


The rectifiers were hooked up to an AC transformer and the rectifier converted AC current to DC current.


I really do not know why AF didn't just use their AC or DC motors for all locos.

Never try to figure how an engineer thinks,


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## mopac (Feb 24, 2011)

I have run a couple of my AF AC/DC locomotives on a HO DC transformer and I
saw no difference on performance.


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## AmFlyer (Mar 16, 2012)

Gilbert made two types of motors for use in engines. The most common is the series wound universal motor. It operates with either AC or DC power. The second type is a DC only motor with a wound armature and a permanent magnet field. Applying AC power to this motor will melt the enamel insulation on the armature winding within seconds. Gilbert never made a motor that will operate only on AC.
As Far as the locomotive numbering, who knows what the logic at the time was! If it has AC after the number the engine has a universal motor and uses AC or DC. If it has DC after the number it has a permanent magnet motor and runs only with DC. 
Only Northerns and 0-8-0 switchers were made with DC motors. Any other type of engine will always have a universal motor regardless of the number. If it is a 332 or 342 just turn it over and look at the motor. The field is visible and is a sure way to know what it is.


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## mopac (Feb 24, 2011)

Strange AF made locos with AC behind cab number if it runs on AC or DC. Would love
to hear them explain that.


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## JMedwick (Feb 11, 2017)

Exactly MoPac. That’s what confused me. I have eschewed the 300AC engines, concerned that it would be very different from the usual AF fare. Guess not.


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## cramden (Oct 13, 2015)

mopac said:


> Strange AF made locos with AC behind cab number if it runs on AC or DC. Would love
> to hear them explain that.


I can only speculate on the suffixes with #'s. A little history about Gilbert; they were already making DC. motors for their HO line starting in 1938. After WWII. they resumed HO and introduced DC motors in the 332 and 342. The catalogues and sales of sets might have been confusing to consumers not knowing if engines were AC or DC. I think in 1948 the first suffixes appeared, maybe Gilbert's attempt to straighten out the confusion. By 1950 with the advent of the Korean War the alnico magnets used in the DC motors were probably needed in military applications and by 1950 DC. motors in Flyer's were done. Also the HO line was dropped in 1950 and never resumed after the war. We will probably never know but it's fun to guess what might have occurred. I should mention that Gilbert did sell HO trains again in 1955 and on but I'm not sure if they were in-house or subcontractors were used instead. Not that familiar with all things HO with respect to Flyer.


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## DrawsOnCad (8 mo ago)

AmFlyer said:


> Gilbert made two types of motors for use in engines. The most common is the series wound universal motor. It operates with either AC or DC power. The second type is a DC only motor with a wound armature and a permanent magnet field. Applying AC power to this motor will melt the enamel insulation on the armature winding within seconds. Gilbert never made a motor that will operate only on AC.
> As Far as the locomotive numbering, who knows what the logic at the time was! If it has AC after the number the engine has a universal motor and uses AC or DC. If it has DC after the number it has a permanent magnet motor and runs only with DC.
> Only Northerns and 0-8-0 switchers were made with DC motors. Any other type of engine will always have a universal motor regardless of the number. If it is a 332 or 342 just turn it over and look at the motor. The field is visible and is a sure way to know what it is.


Following for future reference.
Thanks!


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