@Rod Stewart posted:...
Stan I recall the previous thread and the daisy chaining of two or more detector relays as you show above. I was wondering if that is how it might be done. Thanks for sharing.
I also recall the lengthy thread about 2 years ago regarding use of 153IR's and Itad's for driving interconnected crossing gates, signals and such. I agree that modding a 153IR to isolate the relay common is a bit of a chore considering adding an external relay to the circuit is pretty simple.
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Right, the daisy-chaining is exactly how it might be done. It's all about isolating the common of the SPDT relays. In addition to the nuisance of performing surgery on the 153IR circuit board, that thread also revealed how different versions of the 153IR (all with the same SKU #) had different instructions of which wires/traces to cut, jumper, etc..
Of course the more recent releases of signals and crossing gates have gone to a single trigger wire (rather than two). In such cases you can parallel the NO outputs of multiple 153IR or detector relays such that if any of the relays is active then the signal or gate is triggered.
