I am trying to use side looking IR emitter/detectors from this website in a model railroad application. I am using hardware from CTI electronics that is supposed to work with any IR emitter/detector pair. However, I am confused about how to set this up and would appreciate any advise.
I think I need 2 power supplies for this setup. The first powers the emitter, say at 5 volts. I would then install a resistor to make sure the emitter only gets the 50 milliamps, it’s rated current… This emitter would
constantly be transmitting to the IR receiver. The second power supply would be to the IR receiver. When this receiver is receiving the infrared beam(no train), there would be high resistance and hence be turned off.
When the infrared beam is broken(say by a passing train), the resistance becomes low and allows the signal to pass through the
receiver to whatever it is connected to. I think this setup is correct. However, I have a few questions.
What is the maximum voltage and current the IR receiver can handle? The setup have would connect 5 volts to it. The emitter operates at 50 milliamps, so what does the receiver handle? When the IR path is clear(no train), I need there to be a low voltage, less than 1 volt. When the signal path is blocked by a passing train, I need the voltage to rise above 2 volts. So I am assuming the resistance changes within the receiver depending upon whether or not the IR signal is getting to it or not.
So what I need is when the IR path is clear, the
receiver is off at less than 1 volt and when the IR
path is blocked, the receiver is on at greater than 2
volts.
As you can tell I have no electrical background so a
simplified answer would help me so much