Model Train Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4,360 Posts
Discussion Starter #1
I’m looking for an inexpensive DC power pack for Streets vehicles. I’ve been running my streets loop from a ZW post, but plan to switch over to DC operation. After a little searching, I like the MRC 1370. I don’t plan to ever go to HO or need DCC and I can pick one up for around $50. I was surprised that it only has 18 watts of power, but I guess that’s enough for HO trains. I’m hoping to run as many as 3 or 4 streets vehicles at one time. I know what Lee uses from his book. What are you other Streets guys using? Any thoughts, pros, cons on the MRC 1370?
 

·
Registered
Joined
·
3,076 Posts
If train shows ever start up again you can find dozens for 5 bucks each or less. Another option is a Post War transformer with a bridge rectifier. 90 watt 1033s can be had for 25-30 bucks.

Pete
 

·
Registered
Joined
·
4,360 Posts
Discussion Starter #3
Thanks Pete. No train shows, but you made me think to look on ebay. Bunches of MRC 1370s and other stuff that would work for a lot less than $50.
 

·
Registered
Joined
·
2,085 Posts
I’m looking for an inexpensive DC power pack for Streets vehicles. I’ve been running my streets loop from a ZW post, but plan to switch over to DC operation. After a little searching, I like the MRC 1370. I don’t plan to ever go to HO or need DCC and I can pick one up for around $50. I was surprised that it only has 18 watts of power, but I guess that’s enough for HO trains. I’m hoping to run as many as 3 or 4 streets vehicles at one time. I know what Lee uses from his book. What are you other Streets guys using? Any thoughts, pros, cons on the MRC 1370?
What is the core reason to switch to DC?
 

·
Registered
Joined
·
2,085 Posts
Replacing the rectifiers would be dirt cheap. $0.50 each for 3 A, 400 V rectifiers at Digikey. Less than 10 bucks including shipping for 5 vehicles. And they'd remain compatible with AC transformers.

One advantage with most modern HO DC transformers is their "pulse Power" feature for consistent low speed operation - a partial duty cycle, rectified sine wave. The constant peak voltage coupled with the partial wave is better for maintaining slow speed under load for the brushed DC motors in HO loco.'s.
 

·
Registered
Joined
·
8,854 Posts
Some comments:
1) Lehigh74 is receiving some 'Streets vehicles I culled out of my herd after going to the wire-following cars. I hope people who notice that I have taken up the wire-following cars don't mis-interpret my doing so. 'Streets is still a very good system and a lot of fun. But for me, the model train hobby is fun mostly because I find and create technical challenges and modeling project opportunities for me: With 'Streets, I had already been there and done that. The wire-following cars are new and fun because, so far, they are a big challenge and have created project for me. I still like 'Streets and think it is cool stuff.

2) I took the rectifier out of all my 'Streets vehicles, even most of the otherwise unmodified factory-made bodies, for what I think is a sound reason. As buil (with the rectifier), they will run on AC or DC 5 to 20 volts, and only go forward. With the rectifier they will no longer run on AC, but will now go forward or backwards depending on the DC-voltage: you can back them up. Only a very few 'Streets vehicles - specifically one version of its 'streets van actually made as a track inspection vehicle by K-Line in the year before and when Superstreets was first released, has an e-unit and can be made to back up on AC. With the rectifier removed, they now go forward and backwards. Yes, they only run on DC now, but note K-Line, Lionel, and WBB RTR sets all came with DC transformers, and used one are easy and cheap ($3) to find at swap meets (not that those are very common now, of course).

3) An average 'Streets vehicle only requires 3 to 6 watts of power, typically running well at 7 to 10 volts and too fast above that.t Inexpensive DC supplies made for N- and HO-gauge RTR sets often marketed under the brand named Lifelike, really do cost only $3 or so at swap meets - probably now on e-bay shipping is more than the cost of unisuch a used. They are rated at something like 15 watts max which will power two or three cars well. In that regard those small Lifelike supplies are good. No-so-good is that while they have a smoothly turning voltage knob, it is actually connected to a set of contacts inside that provides only a small number of steps in voltage: i forget now but I think it was only about eight at most - something like 2 - 4 - 6 - 8 volts etc. Given the vehicles need about 7 volts to move at all and go too fast (at least for me) about 12 or 14, this meant there were about three discrete speed settings I could pick from. This, I thought, was the major problem with those really really inexpensive used N- and HO-guage RTR set power packs for use with 'Streets.

4) Millstonemike's comment about pulsed power is correct. While I used a few bought-at-swap-meet Lifelike DC power supplies I preferred to use two older DC supplies from my N-gauge days that were labeled Tech III. They pulsed their power, providing 16 volts which is chopped in duty cycle from 5% to 100% so that the motors are always getting full power, but only on a part-time, millisecond basis, so to speak. Even an inexpensive one of these has more power - 25 or 30 watts, than you will need for most 'Streets loops, and does a really good job of letting you control power.

And it is really cool to be able to back up vehicles when you want! You can only do that with DC.
 

·
Registered
Joined
·
4,360 Posts
Discussion Starter #8
Thanks for the replies. I got antsy and picked up an MRC 1370 last night from ebay. More than $5, but less than $50.

I will set it up with a DPDT switch so I can run DC for streets cars and trolley cars or DCS for street running of trains.
 

·
Registered
Joined
·
2,085 Posts
The MRC 1370 marketing blurb lists "Accupower Technology for superior slow speed operation". I'd bet that's a partial duty cycle sine wave. Makes senses as it's cheaper to implement partial duty cycle control than linear voltage control with modern electronic parts. And it lists "Momentum" for lifelike acceleration and stopping..
 
1 - 9 of 9 Posts
Top