infrared block signals
- Thread starter NR75
- Start date
ThoroughBreed
Dcc~detail~diesel freak
Have you read this yet?
http://www.wiringfordcc.com/blockdet.htm
http://www.wiringfordcc.com/blockdet.htm
I'm not sure if you're looking for a block occupancy detection system or just a block signal system. If you want to just have signals change in response to block occupancy, Atlas has come up with a pretty neat and inexpensive system. More about it at http://www.hogtrainz.com/ATLASSIGNALS.htm. If you want block occupancy detection that you read from a control panel, that's a lot more challenging.
John P
Active Member
My first thought was signals that emit infrared light, what's the point? Nobody would see them.
But if the idea is IR detection, it's not as simple as you might think. If you have to operate under unpredictable lighting conditions, your sensors may "see" the light beam when they shouldn't. Also at a range of a few inches, it's difficult to get a simple phototransistor to respond to a typical LED at all. What you may have to do is rig up an LED that flashes at a rapid rate, with a filtered circuit at the receiver side that responds to that frequency. Or better still, use a synchronous demodulator that's driven by the same oscillator that drives the LED. None of this is impossible, but it's more than just "We'll put the light here and the receiver there". I've tried this myself and always ended up putting it aside and saying "Let's do it some other time."
But if the idea is IR detection, it's not as simple as you might think. If you have to operate under unpredictable lighting conditions, your sensors may "see" the light beam when they shouldn't. Also at a range of a few inches, it's difficult to get a simple phototransistor to respond to a typical LED at all. What you may have to do is rig up an LED that flashes at a rapid rate, with a filtered circuit at the receiver side that responds to that frequency. Or better still, use a synchronous demodulator that's driven by the same oscillator that drives the LED. None of this is impossible, but it's more than just "We'll put the light here and the receiver there". I've tried this myself and always ended up putting it aside and saying "Let's do it some other time."
