We were just talking about them.
http://cs.trains.com/TRCCS/forums/t/199895.aspx
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Sigh.
Look a few threads below this one for Capacitive Discharged Schematic.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
GP-9_Man11786 How difficult is it to build a capacitor-discharge circuit for switch machines? Normally I use groundtrhows for turnout controll but I am contemplating changes to the layout that require turnouts in hard-to-reach spots.
How difficult is it to build a capacitor-discharge circuit for switch machines? Normally I use groundtrhows for turnout controll but I am contemplating changes to the layout that require turnouts in hard-to-reach spots.
Not very hard. A CD circuit is little more than a big capacitor, charged up by a conventional transformer rectifier circuit. They work with twin coil switch machines. When the turnout button is pressed, juice from the capacitor runs thru the switch machine coil, throwing the switch. The capacitor runs down long before you can take your finger off the push button. This extends the life of pushbuttons, since there is no current flowing when they open, there is no arc across the contacts, and so the switch lasts longer.
You want at least 1000 microfarads and preferably more to hold enough juice to throw the switch reliably . The higher the voltage you charge the cap with, the more energy it holds to throw the switches. I would use a 24 volt transformer, available from hardware stores as a furnace thermostat transformer. That will charge your cap up to the peak voltage (1.414 @ 24 = 33.9 volts) Use caps rated for 35 volts or more. The necessary caps can be scrounged out of busted consumer electronic equipment. They are polarized caps, hook them up plus to plus and minus to minus, otherwise they will smoke and smell bad.
If your CD supply must throw more than one turnout at the same time, you need more capacitance. And the supply will take some seconds to recharge before you can throw a second turnout.
A CD supply won't throw tortoise switch machines.
David Starr www.newsnorthwoods.blogspot.com
www.circuitron.com
They have something for the tortise machine. Might work for what you are considering also. Its near the end of the products.
Modeling the Pennsylvania Railroad in N Scale.
www.prr-nscale.blogspot.com