Risk of damaging the microcontroller. Badly designed circuit.
rtek1000 opened this issue · 1 comments
rtek1000 commented
Hi,
As we can see in the electronic diagram, the LED of the relay can carry out a high voltage return if it fails in the reverse voltage, probably when using a power supply greater than the value that the LED supports in the reverse polarization (generally it is only 5V ).
See details in this issue: mister-grumbler/w1209-firmware#22
Please disclose this design error to avoid unnecessary damage.
TG9541 commented
It's almost incredible that such an obvious design error has been copied hundreds of times and that maybe hundreds of thousands of W1209 boards have been sold!
I would suggest to simply remove LED "Red" or R7 and use one of the DPs of the 7S-LED display as a status indicator.
