PWM to DC

[Madman]

I may have brought this subject up before. I am still trying to work out how to do what I want to do. I have an LGB DUO switching locomotive. Using it on track power with an LGB transformer, it works as it is supposed to. However, using it with my G Scale Graphics Railboss system, it does not.

The Railboss system puts out a form of PWM. All of my other locos, be they LGB, Bachmann, USA Trains, all work well with the Railboss system.

There must be some sort of electronic device that will convert PWM to straight DC, but I have yet to find one. There may be plans available to build one, but I don't want to go down that rabbit hole.

The device pictured only works with the Revolution system. I don't want to get into a whole 'other system.

 

[Rhinochugger]

The answer may be in the loco - PWM shouldn't have a negative effect on a motor's performance, although some motors reportedly whine on PWM.

PWM is quite widely used in the smaller scales to give smooth, slow starting and prevent the startled rabbit method of leaving a station

So, is there something in the LGB Dou circuitry that doesn't like PWM?

 

[Cobalt6700]

Madman can you post some close up pics of the DC DUO control board in this thread?

LGB DUO coupler system - how it works (on DCC Loco).

I need to interface with one of the LGB PCBs controlling couplers in the LGB DUO shunting Locos. I did a little investigation into the circuit and thought others might find it useful information. I’m assuming that all of the DUO system couplers (as in the box with the motor in) work in the same...

www.gscalecentral.net

I would suspect the easiest way to make the couplers work is to loose the DC DUO board and run something like the DCC DUO board (or relays), which can be driven by the sound/function outputs on the Railboss controller.

 

[Madman]

Madman can you post some close up pics of the DC DUO control board in this thread?

LGB DUO coupler system - how it works (on DCC Loco).

I need to interface with one of the LGB PCBs controlling couplers in the LGB DUO shunting Locos. I did a little investigation into the circuit and thought others might find it useful information. I’m assuming that all of the DUO system couplers (as in the box with the motor in) work in the same...

www.gscalecentral.net

I would suspect the easiest way to make the couplers work is to loose the DC DUO board and run something like the DCC DUO board (or relays), which can be driven by the sound/function outputs on the Railboss controller.

That sounds promising. Del Tapparo declined to delve into anything to do with my DUO loco. I suspect he's happy with the status quo and don't want to risk any fallout.

That said, there are two electronic gurus on Model Train Forum that I may post the question to.

 

[Dan]

In order to operate the factory LGB duo on DC one needs to slowly turn the speed, stop while uncoupler works, then speed up. Unfortunately pulsed power really does not have linear speed as pulses are sent out at full voltage, it is the spacing between these pulses that determines the motor/engine speed. There are some DCC decoders that do not like these pulses and to run these on pulsed power systems one needs a filter to 'smooth' the pulses to almost pure DC. The MRC 6200 is one unit that these filters work great on as some DCC engines run but very slow until the filter is added to the MRC6200.