The transistor with the free leg is actually a photo transistor. The first led in circuit is IR but there's no adjustments for that nm range.So I'm forgetful and I keep leaving the house forgetting to latch the door in the other room. This is designed to put the status led at the main door and sense the reflection of IR on the latch of the second door. If it's unlocked I get a warning light as I'm leaving. It's in the breadboard now and working very well. I kept upping the resistance until I got the desired behavior but I am uncertain if the values are sound and not overdriving anything. The simulator doesn't help because I have no way to SIM the photo transistor. Any comments or calculations greatly appreciated.
