• How to adapt the 74v outlet!

  • General discussion about railroad operations, related facilities, maps, and other resources.
General discussion about railroad operations, related facilities, maps, and other resources.

Moderator: Robert Paniagua

  by SteelWheels21
A while ago I posted wondering if you could power small electronic devices ie: Laptops, PDAs, Cell Phones, etc. with the 74 Volt outlet found in a lot of Motors. The answer was yes, but some modifications may be necessary. I just got this off our local legend Jerry "FogChart" Freadman's website:


It's a device (or series of devices) that safely let you use any electronic device through the 74V outlet OR..get this..through a special adaptor that plugs into the reading lamp socket. How cool is that!!??!! The stuff is a little pricey but if you're a gadget freak or hesitant to just plug in, it's a safe alternative. Check it out.

  by Guest
Wow, that rocks. I have two batteries for my laptop, it would be wonderful to be able to plug the thing in instead. The extra battery was $100+, so the converter seems like a good deal...thanks for posting the info!


  by steam371
just think, in the Green Goats, there is not only air conditioning but a 110 volt plug in

  by Guest
Also on my wish list is a friggin cup holder on the Conductor's side.


  by SteelWheels21
Some of the units, I can't remember which model, have the cup holder molded into the desk. Big enough for a Gatorade quart.

Funny story: On one of my student conductor trips I got to run the show as opposed to watching. I had all my stuff laid out, along with some snacks for the ride. The front door had popped open when we were underway, probably about 45 mph. When I went down to close it, it forced itself open farther, which caused a wind blast that blew all my paperwork, a half can of pringles and a half bottle of coke out my open side window.

  by jackal
I just ordered the 100-volt converter (74v DC to 12v DC--I already have a cigarette lighter charger for my laptop) from Locoverter. This thread is old, so I thought I'd bump it and ask if anyone else has had experience with the Locoverter since this thread was originally posted.

Also, according to a site linked to from Locoverter's How-To, it may be possible to plug a laptop's power charger into the 74v DC socket IF your power charger is voltage-sensing (usually displayed as accepting 100-240v on the power brick itself). However, while these probably won't fry the charger or the laptop instantly, they may still suffer from premature wear.

Anyway, with the 'verter, maybe I'll finally get some good use out of my Netflix subscription. Er, only on the deadheads, of course... :-)

Our 70MACs with Comfort Cabs/WhisperCabs and desk-mounted controls have the cupholders molded into the desk on the conductor's side. Not sure if it's different on other similar models or on the CN's Comfort Cabs with the standard control stand.

  by UPRR engineer
I havent bought one yet, freind of mine i work with says he's figured out what he needs to build one himself for about 35 bucks, told me to hold off. I dont know if id plug my labtop in, but i have a subscrition to Blockbusters.com. :wink:

  by slchub
Hey Steel and UPRR,

I got this one from an old head on the Ogden-Elko side. He took a regular extension cord, cut off the plug, attached alligator clips to the wires and then clips the alligator clips directly to he knife switch behind the circuit breaker panel door. Works fine. I've done the same thing and have run the laptop, cell phone and Sirius boombox from it. No problems at all. If your item does not power on, flip the clips from one side to the other.

  by David Benton
UPRR , unless your friend is am electronic s eginner or technician , i wouldnt hold my breath .They can be made , but theyre quite complicated little things .

Radio Shack sells an adapter, for ac/dc voltage into a cigarette lighter outlet, for plugging in cell phone chargers, lap tops with cigar type plugs, etc. It has no problem using the outlet, on the control stand of modern diesels, to charge/operate many small electrical devices. The guys I work with use if to listen to their Sirius radios, charging cell phones, etc. The thing costs less than twenty bucks............. :wink:

  by GN 599
They dont even like us using cell phones while the train is in motion. I can only imagine what managers would think of this stuff. :-D But heck what else am I gonna do while I am sitting in a siding for three hours. :P
  by Dougman
One needs a DC - DC converter that can take high voltages up to 74V which in the past have not been so common. They are starting to become more common though.

Adequate Energy sell a dc converter that can take any input (between 16-84V dc) and convert to 12V dc.

Axiomatic also sell one, that can take a 72V dc input and convert to 12V.

  by slchub
Or just plug that bad boy in. I've done it several times to the plug in on the hoggers side of the cab with my cell phone charger, laptop power supply and Sirius boombox. If the cab does not have a plug, then I take out my extension cord which has the plug end cut off and has two alligator clips attached, and I clamp the alligator clips to the knife switch in the circuit breaker panel. No problems. I've been doing this for two years now.

  by David Benton
most laptop power supplys etc , are switchmode . generally they will take a wide voltage range , and d.c , or a.c of varying hertz . But i wouldnt try it !

  by freshmeat
Here is a great source for 12VDC, unless you are running DP. ON the DP radio in the nose, there is a black/red wired plug that powers the DP radio. It is a small plug and one side is male the other side female. I've seen guys have a cig. lighter femal end wired onto that and use the 12VDC from the DP radio to power whatever.

Now here is the best one, if you dont need your refrig. Get a plug that is the same type used to power the refrig. Wire the thing into a small power strip and you have 115VAC and about 4 plugs to use. If you are conservative with the power usage, you can run a lot of things off of it. No water heaters for soup though. (You can plug heating elements right in the 74 VDC outlet.) I've even heard, not seen, of guys that have the refrig plug and the same female plug on the wire so they can use the refrig. This is more than enough to use a laptop, DVD player, XM boombox, cell phone charger or about anything else you want to use.

The real trick is to be able to get the wires hidden or taken down before you get boarded. ON that note, Altech Lansing makes a great book type speaker that will plug into the 74 VDC and you can put a battery powered XM radio unit on it and have very few wires. Cell phone anteanas are another story.