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DaOld Man:
I found another version of the drive way alerter at Harbour Freight.
This one had a sticker that said "channel 1" on it so I figured it was the same as the first one I converted. And with coupon it was a little over 9 bucks so I thought "what the heck".
I took it apart and it is yet another version of the board. (Sorry no pics).
It does use the same chip as the first one in the transmitter, but the address jumpers are surface mount pads that you have to bridge with solder to set.
Also this one is only using 4 of the possible combinations to address it. It uses the same chip, so you could still address it on the unused pins of the chip, but you'd have to do some fancy soldering.
The receiver end is different too. It uses surface mounted LEDs, but the good news is that they use ground for common, so the SCR I have works.
Just have to cut back some of the trace to the LED and solder the scr in to it.
EXCEPT: The scr would not stay latched on. I first thought i had a bad scr or damaged that one with solder iron heat, so I swapped it out, but only to have same results.
After some trouble shooting, I found they used a different LED driver chip on this version. When the output of the chip goes high, it turns on the LED, but when the chip commands the led to turn off , instead of floating like the first version did, it goes to ground. This effectively turns off the scr, hence scr not latching on.
I fixed this by adding a diode in the gate circuit, to block a negative (low) signal from the scr.
It works, but this is 3 different versions of the same device, so who knows what they will come up with next?

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