"If there is an active short circuit you can protect the frog connection by wiring an automotive bulb in series with the hot frog. Since the archives are temporarily unavailable, I can't offer a suggested part number. Different bulbs will limit the load to anything from 1.4 amps up"
If there is interest in the use of light bulbs, a discussion of the pros and cons may be found here: http://www.wiringfordcc.com/track.htm#5-4
thanks for the replies. it seems to make better sense now.
without a locomotive ON the frog, there is no connection between the two rails; thus no amps being sent thru the wires on the isolated frog. having the tortise contacts 'slide' to the other side with no amps being sent thru the wires will then nullify my concern of mini shorts on the contacts causing mini burn spots and shortening the life span of the tortise's ability to power route the isolated frog.
as usual, you guys have the answers when i can't think outside the box.
Unless there is an active short circuit going on, the contacts that power a hot frog only have to carry locomotive power - probably less than one amp.
If there is an active short circuit you can protect the frog connection by wiring an automotive bulb in series with the hot frog. Since the archives are temporarily unavailable, I can't offer a suggested part number. Different bulbs will limit the load to anything from 1.4 amps up.
Chuck (Modeling Central Japan in September, 1964)
As long as your overload protection is working the contacts should handle the high current short term. The contacts will not be opening or closing during the short.
I have my Tortoise motors wired(one set of contacts) for powering my Atlas frogs in the staging area. There have been mishaps, but the Tortoise machine have survived with no problem. If you are concerned, get a 12v relay with HD contacts and have the Tortoise contacts switch the relay on/off. I thin it is overkill, but if you need 'bullit-proof'....
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
i have read and understand the instructions for completing the electrical components to operate the tortise switch machine: power feed, wires, DPDT, LED's, etc.
when it comes to power routing the isolated turnout frogs, the instructions state the aux contact can safely handle a 1 amp rating while moving and a 4 amp rating when stationary. these ratings can be doubled IF both sets of aux contacts are used simultaneously (2 amp moving , 8 amp stationary). with the 5 amp and higher DCC systems, this rating would surpass the 2 amp moving contact amp rating.
does anybody have any expierence with this set up? would the contacts burn out quickly? are there other options to provide reliable power to the isolated frogs?
please keep the replies on topic. if my question isn't clear, i can explain further.
thanks for all the advice.