I bought a BLMA dual head block signal yesterday. I want to install it without crazy block detection and all that jazz. I would however like to manually control what color it is displaying. What do I need to make that happen? I already have a single post double throw toggle switch. What else would I need? Thanks!
You need a 3 pole switch (or rotary switch) for each head. Since there are 3 possible aspects each head cna display (discounting the flashing ones - that's even MORE stuff you need), you need a switch with 3 positions at least. A DPDT isn't going to cut it.
--Randy
Modeling the Reading Railroad in the 1950's
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Is there some consumer item out there that will make this where I can control it all from one switch?
Well, there are 9 possible combinations of both heads, although not all are actually used. A two-pole 6 position rotary switch could be wired to give you 6 of the 9 combinations simply by turning the switch from position to position.m but that would also require diodes. Two independent switches, one for each head, would make things much easier to wire, each switch would have a positon to select red, yellow, or green for each head. Activate whichever you want, whenever you want, just by changing the switch postions. I don't knwo how to make it any simpler - you simply treat it like there are 3 individual lights, forget the fact that they are all mounted in a signal head, there are just 6 individual circuits. So you COULD also just use 6 SPST toggles. It gets wire just liek hookign a single light bulb and switch to a power supply. Repeat 6 times, and you cna control the signal simply by turning various switches on.
Pretty sure they are LEDs, so you need ot use resistors, The instructions should tell you.
3 position switches are not readily available from places liek Radio Shack, but you can get them from a real electronic supplier. Radio Shack does stock 6 position rotary switches, you could just use 2 of them and only use 3 positions on each.