I have a cross over on my main line using two Tortise switch machines. I built a signal bridge with 8 bi-color (red/green) LED's to indicate switch positions from both directions, With this many LED's putting them in series with the tortise motors will not work. I tried it and once the motor starts to move the LED's go out, not enough juice to go around. So I am using a DPDT slide switch with 12vdc coming in on one end and crisscrossing to the other. This is working fine both for switching the two tortise and lighting up all of the LED's. The problem is with a full 12v going to the Tortise motors the points move very fast and they make a heck of a racket moving. So my question is how can I reduce the voltage on the tortise without reducing voltage on the LED's? Thanks for any responses.
Try running putting a couple of diodes ahead of the torti's.
You could also try wiring the torti's in series so each gets 6 volts. I think they will run at that voltage.
To wire in series. 1 lead of each torti goes the the power source and the other goes between them. So you go from switch to torti number 1, out of torti 1 and into torti 2, then out of torti 2 and back. You might have to reverse polarity on one of them depending on the result.
Good Luck.
Springfield PA
Hamltnblue You could also try wiring the torti's in series so each gets 6 volts. I think they will run at that voltage.
Tks HB. I think I will give "series" a try. I have a bunch of diodes but the "series" solution looks easier. I'll keep u posted,
I take it you actually wired these LEDs to the contacts - 8 series LEDs drops almost 17 volts so naturally they won;t work in series with the Tortoise motors.
6V might be a bit too low, somewhere around 9V to the Tortoise seems to be a sweet spot between speed, noise, and holding power. Maybe stick a couple of LEDs in series on your control panel. With a 12V input, one bicolor LED on the panel in series with the motor will drop you to under 10 volts. A couple pairs of regular diodes wired back to back will provide a voltage drop as well, about .7 volt per pair.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
HB - I wired the two Torti in series. The noise level only went down a bit but the speed is much better. switching speed went from less than a second to about 3 seconds. I push/pulled on the throw bar to see if the holding pwr had been reduced and it was solid.
Randy - If I remember correctly fm a year ago when I made up the signal bridge each signal aspect consists of two Bi-color in par. The front pair is also parallel to the rear pair on the same track. The other track is the same but a sepaerate set of wires. I think that makes sense. These are three legged bi-color LED's. Even though the noise level is a little lower with the two torti in series I notice they are not nearly as quiet as the rest of the Tortise motors that are being driven fm my DS-54's? Of course they all have two LED's in series with pins 1 and 8 reducing the voltage somewhat,
Randy - does it matter what kind of diode you use in series to slow the motor down? I have several 1N4007 1 amp @ 100v and a couple of 1N4001 1 amp @ 50v?
Anyway problem solved and thank you gentlemen for your help.
1N4001 and 1N4007 are the same except for the peak inverse voltage (PIV) which is the most the diode can take in reverse (ie, when the current DOESN'T flow) before they fail. 4001 is 50 volts, 4007 I think is 200, not 100. Since we're dealing with 12 volts here - 1N4001 is fine, but if you have 1N4007's on hand they'll work just as well. The 4007's are probably physically larger, although for under layout use that also is probably not an issue. I've used 1N914 diodes (the ones that are usually in the clear glass package) with Tortoises as well, they can handle up to 200ma which is well over a draw of a Tortoise.
Keep the original circuit design (leds in line with tortoise power) Increase the voltage by 1.7->2 Volt increments till it works.
Each led in series causes ~1.7->2.1V drop across the line. If you drop below 6 Volts (roughly 3 leds 12 - (3 leds*2V/led) = 6) then your tortoise won't work very well.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!