ken's trains posted:... I could add a 2nd voltage regulator to supply 5V to the detection/override functions. I guess it's a matter of what is most convenient and effective. Also, it doesn't seem reasonable to keep those components always powered even if not being used--
Many options. My observation was you shouldn't need a 2nd relay. That is, the control panel toggle switch could either (1) block triggers to the relay modules, or (2) as you suggest simply cut power to the IR relay modules themselves.
If using method 2), DC-to-DC voltage regulator modules (to convert 12V DC to 5V DC) are about $1 on eBay with free shipping from Asia.
ken's trains posted:...By the way I did keep increasing resistance values and am using 15K.
By the way, if I haven't been too much of a pest, I would really like to know why current level (if that's what is the controlling agent) through an IR sensor affects its' sensitivity (or at least that's what I observed).
If I understand your question, the IR sensor is not binary "on" or "off" like a toggle switch. Instead, the electrical resistance between the 2 terminals varies depending on the amount of IR energy hitting it. More IR energy lowers the effective resistance. In your application the IR sensor (photo-transistor so actually a semiconductor) is effectively behaving as a garden variety photo-resistor where the resistance between the 2 terminals decreases as light increases.
Apparently you were having a sensitivity issue so that's why I suggested you increase the trigger resistor value from 1K to 5K or whatever. Increasing the resistor value decreases the amount of current available to trigger the relay. In your application, the IR sensor shunts or diverts the trigger current. Increasing the resistor value means less current needs to be diverted to keep the relay off when the IR beam is present. Thus this increases sensitivity since less IR energy is needed.
