Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Question about old time DC wiring

642 views
5 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    June 2008
  • 524 posts
Question about old time DC wiring
Posted by tin can on Tuesday, May 19, 2020 11:01 AM

A long time ago, in a club far away, we used two pole, multi position rotary switches to assign DC cab power to blocks.  We used off the shelf Radio Shack components.  I was thinking about earlier today, and did some online searches.  Radio Shack only carries a DP rotary switch rated for 0.30 amps at 30 Volts AC.  Other suppliers carry such switches, but anything rated for an amp or more is expensive. I know our DC power supply was good for 5 amps for each cab.  Were we just stupid back then, or were there more options for rotary switches in the good old days?

Have no clue if you could do somthing similar with DC vs DCC today; with 14 Volts and 5 amps on the DCC side.  

Let's just say I was thinking about this....

 

 

Remember the tin can; the MKT's central Texas branch...
  • Member since
    July 2009
  • From: somerset, nj
  • 3,090 posts
Posted by gregc on Tuesday, May 19, 2020 11:26 AM

tin can
Were we just stupid back then, or were there more options for rotary switches in the good old days?

i believe there were more options back then because there was greater need

things today are more efficient and are controlled more efficiently.  Instead of routing power to high power mechanism (e.g. motor)  thru control components manually moved by a person, a low power device would control a high power device (relays) next to the high power mechanism.   More likely, some device with a processor is controlling power to a mechanism using solid state componets (e.g. triac, scr, mosfet) using low power circuits.

with DC model railroading, all the power to a locomotive is routed thru the operators controls.   

With DCC, all the power from the booster is routed directly onto the track and the operator sends very low power commands to the command station which sends a low power DCC signal to the booter which controls the polarity on the track.

greg - Philadelphia & Reading / Reading

  • Member since
    June 2008
  • 524 posts
Posted by tin can on Tuesday, May 19, 2020 11:36 AM

Thanks, Greg.  That makes sense.

Remember the tin can; the MKT's central Texas branch...
  • Member since
    February 2002
  • From: Reading, PA
  • 28,173 posts
Posted by rrinker on Tuesday, May 19, 2020 1:52 PM

 The club I used to belong to was DC. This was about 23 years ago, the only rotary switches we had were the same low current types. We wired those to relays, so the rotary switch only controlled which relay was energized, and the relays had higher current capacity contacts. 

                                   --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    February 2005
  • 724 posts
Posted by davidmurray on Tuesday, May 19, 2020 6:29 PM

I have some rotary switches in the shipping bag they came in.  about ten years old.  They were from www.allelectronics.com  phone 800-826-5432.  six postion rotary.

I use telephone wire from the barrier strips (terminal block)  to the switch and then back to track.

#26 wire will not handle a lot of current, but no problems.

 

David Murray from Oshawa, Ontario Canada
  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 7,958 posts
Posted by SeeYou190 on Friday, May 29, 2020 12:49 AM

My friend Randy used three position two pole rotary switched on his layout as cab selectors for block wiring on his N scale NORFOLK SOUTHERN layout.

The center position was not wire to a cab, so it was off.

The basically made the three position rotary switches into DPDT center off switches, but they were much nicer to use, and looked much better in his control panels.

-Kevin

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!