I want to wire the above so that the up switch position shows green, and the down position shows red. Bottom right is terminal 1, up 2, up 3. Bottom centre is T4, up 5, up 6. Bottom left is 7, up 8, up 9.
T 1-6 are as a normal DPDT toggle. T8 is an isolated common to 7 and 9 which are the LED terminals.
With the switch up, a multimeter shows a green light with common 8 negative and 7 positive (as required). And switch down, common 8 negative and 9 positive shows red (as required)
How do I wire the motor in the circuit using it as a resistance for the LEDs?
12 volt 500 ma DC power supply.
I think you have the wrong switch to do that with. It sounds like you have the M2122TCF, what you want is the M2122LCF which has the LEDs completely isolated from the toggle, in which case you woudl connect one of your leads goign to the motor from the switch terminal to pin 7 of the switch and then pin 9 out to the motor, putting the pair of LEDs in series with the motor power. Based on your description of the conenctions to the LED, you have the synchronus version of the switch and you want the isolated so it's effectively just a bicolor LED int eh switch handle unaffected by the handle position. Data sheet with circuit diagrams here:
http://datasheet.octopart.com/M2122LCFW01-NKK-Switches-datasheet-11628496.pdf
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi Randy,
The switch case shows M-2122TRM, and according to their circuit sheet, it's a synchronous bicolour LED. The LED terminals check out as per my test.
In any case I may be $220 out of pocket for switches because the Cobalt data sheet states not to connect LEDs in that way with the digital motor. Confusion reigns!
Ron Hume.
I suspect the warning is due to the Cobalt motor drawing more than the normal 20-30ma limit of a typical LED. A friend tried to wire a bi-color LED in series with a Micro Mark switch motor and burned out the LED immediately. That switch motor draws over 60ma - a Tortoise draws about 18ma at full stall.
Modeling BNSF and Milwaukee Road in SW Wisconsin
The T in the part numer is synchronus, and that's NOT what you want if you want the LED to be controlled by an outside influence. If you just want it to flip with the handle position, just hook the two leads to the power feed going to the switch (with resistors) NOT in series with the motor. Which switch terminals are connected to the LEDs changed with the handle position - that's the synchronus version. The Isolated version of the toggle is like if you purchased a toggle switch and a seperate bicolor LED. That is the sort you would put in series with the motor.
As for not doing it with the Cobalt. The original CObalt drew too much current and would blow LEDs if you tried that. There is the analog IP Cobalt, which has a low enough current draw to work like a Tortoise. There is also the Digital IP Cobalt, which sounds like it has a DCC decoder in it and the connections for a manual switch do not actually feed power to the motor, but rather control the electronic circuit. LEDs in series won't work there.
The good news, you have the Synchronus version of the toggles so you cna just have the LED controlled locally rather than in series with the Cobalt motor or anything like that.
More bad news, it appears the Cobalt IP Digital wants pushbutton momentary contacts for local control, not a toggle like the IP Analog. So if you have IP Analog you are ok, but IP Digital, the toggles are out.
Recently found this thread about wiring turnouts with LED switches. In talking to a friend he told me that I could control the Atlas Turnouts with SPDT switches. Based on the information above, I purchased M2112LCFW01 switches from Mouser Electronics (On - None - On, 6A, NKK Illuminated Toggle). What I need to know now is how to wire the switch with the turnout and power supply. Any insight would be helpful.
Jeff
You cannot control Atlas turnouts with just a SPDT toggle, unless it is a momentary toggle, which those do not appear to be. A lighted SPDT toggle would be completely useless for Atlas type turnouts, as there cannot be continuous power or the switch machines will burn out.
You can use a SPDT toggle in conjunction with a normally open momentary conatct pushbutton - but there still would not be power to run the LED indicator in the toggle. And it may just blow out the LED as the proper voltage to run Atlas switch motors is higher than 12 volts.
The only way to get position indicator LEDs with Atlas switch motors is either a more complex circuit which lights LEDs as well as sends a momentary pulse to the switch machine, or to connect an Atlas Snap Relay in parallel with the switch machine, which then gives you two sets of SPDT contacts which you can wire to some LEDs
Randy, thanks for the info. I will check into the Snap Relays.
Another item of discussion. I also suspect that there is not enough power being provided ot the Altas Turnouts. I get the buzz but the throw does not always complete. I am attempting to run the accessories (turnouts) off of a very old transformer. Any suggestions on the best power supply or transformer to use to update my electrical?
Yes, build or buy (Circutron Snapper, for one) a capacitor discharge power supply. It will give the switch motors a very strong but short pulse which will make them snap over AND if the button gets stuck, the current is limited so as not to burn out the coils.
It's a super simple circuit to build, however with the death od Radio Shack stores it's not as easy to get the parts, you'd have to order them from somewhere. Quite simple, a transistor, couple of diodes, large capacitor, and a sandbar resistor. You can add an LED and resistor that lights up when it's charged but not really necessary. What happenes is that when you press the button, the capacitor discharges a strong pulse to the switch motor, making it move, but as long as you hold the button it can;t recharge and current stays low. Let go of the button and the transistor allows the capacitor to quickly recharge - there are simpler versions without the transistor but they can take some time to recharge, so if you have a train heading for the abyss and need to quickly throw 3 different turnouts to get it back on course, the fast recharge with the transistor can be very handy. I built one back in the late 70's when I was about 12 and it may still work, although I haven't used Atlas switch machines in forever. Mine came from the book "Practical Electronic Projects for Model Railroaders" which I'm pretty sure is out of print, but if you google it you will find many example circuits. I used an old N scale power pack as the power source (and also used it to light my buildings), saving the good power pack for running trains. Despite the realtively low power of the train set pack, it worked fine, and after installing it I never again burned up a switch machine coil. And the N scale ones were always more delicate than HO ones.
Appreciate the write up. Amen, on N Scale turnouts being sensitive. I noticed today in my testing that I have melted 3 of them. I will investigate the capacitor discharge circuit to see if I can get these things working correctly. Thanks again.