stan2004 posted:Also, have you guys considered 2-aspect signals? The time-delay and inherent flicker suppression is a nice feature that few (if any?) off-the-shelf 2-aspect signals (e.g., dwarf) have. I haven't reviewed your circuits to see if this is a no-cost / just a jumper change.
Stan;
Well our simple circuit R5.4 (2 transistors, 2 diodes) version works well as a 2 aspect signal timer also. All you do is replace the R6 270K resistor (yellow release timer) with a 1N4148 diode, and presto. When tripped the signal goes red as it should, then after the prescribed release time it goes straight to green.
Actually there is a split second flicker of yellow, but as long as there is no yellow diode in use, you don’t even notice it. In my testing it made no difference whether an led was attached to the yellow output or not.
You would not be able to use this circuit to run both 2 and 3 aspect signals together however. There would be a long gap of no light on the 2 aspect head when the yellow is lit on the 3 aspect head.
I plan to document all this in the User Notes. 
Rod
