Are some turnouts designed such that the electrical conductivity from one end to the other depends on the point rail making physical contact with a side rail? That seems like a dicey proposition to me, but perhaps I'm just pessimistic.
Thanks.
Hi
You might want to read Allan Gartner's Wiring Turnouts page on his web site on DCC. It can be 'dicey' even with turnouts that are DCC friendly.
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/
feh Are some turnouts designed such that the electrical conductivity from one end to the other depends on the point rail making physical contact with a side rail? That seems like a dicey proposition to me, but perhaps I'm just pessimistic. Thanks.
The answer is, "Yes, but..."
Ancient kit turnouts, and Shinohara turnouts from the 1960s, depended on solid point contact, OR on use of the electrical contacts on the switch machine to power the frog. I believe the same applies to so-called "Electrofrog" turnouts today.
My own hand-laid solid frog turnouts have frog power routed through contacts. The points are electrically dead and not connected to anything. The closed point is powered by the sliding contact made when it rides up on the stock rail. The open point, being dead, can't cause a flange-back short - one of the major problems with points that are electrically connected to each other
If you have a multi-meter, it's easy to tell the electrical characteristics of your turnout by using the RX1 scale to measure resistance. If the closure rail has no readable resistance when checked against the adjacent stock rail (zero Ohms) and the same is true of the same rail beyond the frog, you have an "Insul-frog" or non-power routing turnout. The frog should be electrically disconnected from everything (and may be black plastic in some models) If the frog extension and closure rails measure infinite resistance unless the points are held firmly against the stock rail being checked, you have a power routing model - and would be well advised to use one set of the contacts on the Tortoise or Rix machine to guarantee appropriate power to the frog.
If you prefer manual point throwers to machines, check to see if they have electrical contacts. I personally have used (and still use) DPDT toggles or slide switches at the fascia line, connected to the points with fishing line. The points are held in normal position by suspended weights - either fishing weights or used 1/4 - 20 nuts.
Chuck (Modeling Central Japan in September, 1964 - on hand-laid specialwork)