Need help understanding the AVC (Accessory Voltage Controller)

Is the AVC similar to the TPC?  The pictures on the website look similar, but the template for mounting in the manual looks like the ASC/BPC footprint with tabs on the side and a programming jumper sticking out.


I am in the midst of measuring the amount of load that various devices put on the serial data output, and I am expecting that the AVC has an optocoupler input like the TPC.


The TPC and AVC are the only Lionel devices that I think have optocoupler inputs, and the ZStuff Data Wire Driver also has an opto input.  The ASC/BPC etc. types seem to have direct high-impedance inputs that draw microamps.


Thanks in advance for any help.

Original Post

Hi Dale

The AVC looks EXACTLY like the TPC 300, it is black and the same footprint and wiring posts. I have sent a picture.


There is the BPC, ARC, OTC, AMC, ASC as separate devices. The ASC and BPC come in the IC version along with the TPC.


Lionel added TMCC control to a couple of accessories, like the Crane. I think a Coaling Station is another, and there are more.


hope this helps your endeavor.




Photos (2)

Well, there is the ARC-Action Recorder Controller.  I never understood the functionality of the AVC.  It controls the amount of juice given to accessories, but they are all at the same setting.  It seems I did the same thing without an AVC, using the variable outputs available on an AMC.  It is the only controller box I haven't used.

I guess if you are using Ross switches with DZ 2500 machines, that would count as well.

I think there is a TMCC culvert loader & unloader.  I have my crane & my log loader powered by AMCs.  Later they came out with both with the capabilities built in.  And the ability to make a recording on both as well.  Mine are still working great the original way. 

<<Was there also a TMCC Culvert Loader?>>


Dale, I think it was mentioned but the CC Culvert set is TMCC with radio receiver boards.  I have the set and both are controlled by an ENG command.

PRR by Lionel

Eastern PA Mountains, between Oley and Boyertown


  The accessory voltage controller is the biggest waste of $130 I have ever experienced.  I bought it believing there would be either multiple outputs which could be set at different voltages and addressed by an accessory number, or multiple program addresses which could be adjusted and stored for particular accessories. HA HA!  The thing is nothing but a transformer with a single adjustable output.  Sure you can fine tune your accessory voltage provided that every accessory on the circuit works best at the same voltage.  If not, you have to reset every time you use any accessory, keeping in mind that all other accessories on the circuit will also be set to that voltage.  I created an accessory bus powered at 18 volts, and put a rheostat between the bus and each accessory.  Each rheostat is set to the best voltage for its own accessory.

Much better control than the AVC.



There is also a DZ-2001 Data Wire Driver which I have as the very first item on the Command Base "chain" of devices.  Sequence is:

Command Base

DZ-2001 Data Wire Driver (controls all DZ-2500 switch machines)




AMC (this is its eventual position, but not yet hooked up)


Hope this helps,



TCA, NMRA, PRRT&HS Modeling the PRR Panhandle Division between 1948-1957.

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