Sierra9093
New Member
Hi folks,
I am working on a small project to build some LED lights to place in signal bridges on my model railroad layout. The purpose of these light is to indicate the train direction on a given track by looking at the color on the signal bridge. Red would indicate one direction and green would mean another.
So far I have worked out that I would want to take a tiny amount of current/voltage from the track to trip a larger current/voltage via a pair of transistors. I have enclosed a picture of the circuit as it now stands on paper and from what I can tell, it is probably no functional. But this is as close to a schematic that I could think up to base this upon. The maximum track voltage is around 15VDC. And from that voltage I would like to tap a small current to trip the transistors. I want to keep the base voltage/current at a minimum because being a model railroad, I would like to conserve as much voltage/current as possible for the operation of the locomotives.
I am an electronic novice, so any suggestions from anyone familiar with this type circuit or can figure out what I am trying to do would be very helpful and greatly appreciated. I have two DC power sources that represent the track to switch up the polarities. The 20V power supply is the supply voltage for the signal lights. Thanks!
I am working on a small project to build some LED lights to place in signal bridges on my model railroad layout. The purpose of these light is to indicate the train direction on a given track by looking at the color on the signal bridge. Red would indicate one direction and green would mean another.
So far I have worked out that I would want to take a tiny amount of current/voltage from the track to trip a larger current/voltage via a pair of transistors. I have enclosed a picture of the circuit as it now stands on paper and from what I can tell, it is probably no functional. But this is as close to a schematic that I could think up to base this upon. The maximum track voltage is around 15VDC. And from that voltage I would like to tap a small current to trip the transistors. I want to keep the base voltage/current at a minimum because being a model railroad, I would like to conserve as much voltage/current as possible for the operation of the locomotives.
I am an electronic novice, so any suggestions from anyone familiar with this type circuit or can figure out what I am trying to do would be very helpful and greatly appreciated. I have two DC power sources that represent the track to switch up the polarities. The 20V power supply is the supply voltage for the signal lights. Thanks!
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