Hello All,
I have this crazy idea for a project and hopefully, I don't destroy any of my equipment in the process. I got this idea when a train and/or the cars derail and I want to make some type of universal utility train to run over there and assist with the legacy crane on battery power. Of course, I could have separate blocks on a dual main line, but what happens if it's in an odd place like on a switch or in a yard or tunnel when the AC hot power gets cut off.
My goal of this project is to run DC power into my train, but keeping the legacy/tmcc function. If I can successfully get the engine running on battery power and somehow bridge DC to AC power's common wire to my layout's common wire phased together to retain the legacy/tmcc function because the common will always have the signal from the legacy base station. I'm under the impression the signal will be there even if the hot from the transformer is off. I also want to mention I have the DCC Speciality's solid state circuit breaker board between my transofmrer and track to cut off the hot wire during a short.
I'd be happy and I can start applying this method to a legacy crane (if anyone wants to donate one to this cause I'd be happy to accept and return after), which I'll invest in one if the engine project is successful.
I tried to look around for references on powering up a locomotive with battery power on the forum. I only found these semi-useful links. I saw some for Lion Chef engines, which I know can run on DC power, but it's not relevant to my project. As I want full legacy/tmcc function the entire time. I also saw some other posts about successful conversions but it sounds like changing the boards to from Lionel to some DC capable of board and it sounded like I'd be running DCC at that point.
https://ogrforum.ogaugerr.com/...s-sw-battery-powered
https://ogrforum.ogaugerr.com/...owered-by-dc-battery
Base off some research on the forum I saw it was mentioned to look around for a small pure sine wave AC inverter in the 40-50 watt range. I'm not sure if that comes in a form of a circuit board because a quick internet search shows what appears to be power inverters for cars using wall outlet type plugs.
Another one pointed to Fern Creek Electronics Inc., I didn't call the guy, and I was hoping the original person from my second link would have returned with more information about what happened when he called him. This route sounds extremely expensive and custom made as it looks like it's meant for special solutions equipment for studios and Hollywood type of industries.
My last part of research came from me not knowing that a full bridge rectifier from AC-DC is only a one-way thing and cannot go the other way around. I found this theory called an H-bridge and it appears that this is how those power inverters for cars work. I'm just not sure if they sell a ready made one in a circuit board form and if this piece is only part of the puzzle to my goal or if it's all I need to invest into.
https://en.wikipedia.org/wiki/H_bridge
http://educypedia.karadimov.in...ics/powercontrol.htm
Also forgot to mention that I'm not sure what type of battery to invest into volt, amp, wise, but I'm prepared to install all these components into a non-powered unit and teather it to where I need. If the battery needs to be quite large I'm also cool with using a boxcar or flat trailer to hold it.
If anyone has expertise or insight or further ideas into this I would apperciate this and if I can get it working I'd be happy to share my research into a guide for others who'd be interested in making one for themselves.
Just imagine your utility train running out to the derailed spot, pulling/pushing cars or rerailing your stuff back onto the track without physically touching it. 
Thanks in advance!
