I brought my LGB train quite awhile ago. Now that I am not working full time, I thought was a great time to do my lay out. I plan to switch my tracks using the 1205 and 1215. This will be done by a MCU switching a relay. However, the best understanding I can get from the instruction sheet is that the switch needs 18Vac to operate. I measured the coil's resistance at the switch and found it to be about 23 ohms. Using ohm's law, this gives me 782 mA. This is fairly high current. I do not want to burn up the coil. Am I doing this right?
Yes, solenoid switch motors draw a lot of current but only for a short while. You need to use momentary contact buttons or toggles to oeprate them, you do not leave the power connected. A capacitor discharge power supply is also recommended - this provides a stronger pulse to make the motor move, but if the button sticks it limits the current so the coil doesn't burn out. In smalelr scales where the coils aren't as rubust it really helps protect them, but even these will surely burn out if the power is applied for more than a few seconds continuously.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks, Randy, for the info. I ran into an article at www.londongrs.com/How_To/EPL/EPL.htm. Excellent article on the subject. After reading the article, I decided to use LGB contact, # 17100 with a magnet. The reed switch will send that fast pulse to the switching motor. Again, thanks for taking the time. John