Hello,
I found this site and was hoping that someone may be able to help me with my hall effect keypad. I have a 12 key Honeywell keypad for a wire bonding system that is indicating a stuck key. I would be greatly appreciative of any help on how to identify the stuck key issue as I'm not currently able to make much sense of the hall effect switch.
What I have done so far:
I have identified operating voltage 5VDC
I have tested the output leads and of the 12 individual devices, I see what only appears to be 3 that are working. So by that, I mean voltage measure across the two output leads measure ~.027vcd when I present a magnet to the device the voltage jumps to 1.2vdc. The remaining devices will behave in two ways. (1) the output leads will be stuck at the higher voltage (1.2vdc) or (2) output leads will start off at the low voltage (.027vdc) and when presented with a magnet rise up the 1.2vdc and then when the magnet is removed the voltage stays at 1.2vdc. If I gently tap the top of the device I can get the voltage to drop back down to .027vdc.
I have acquired a few other keypads and they all work like the first key described low voltage with no magnet present and increased voltage when a magnet is present. The difference between them is the High side voltage output. original keys are 1.2vdc the new working keys are 4.5vdc. I'm afraid to install the new devices because I don't know what the downstream voltage should be. I currently assume it to be 1.2vdc and I would suspect 4.5vdc could potentially cause damage to circuits elsewhere in the system.
If anyone has any input on my testing methods or a better understanding of these hall effect switches function that would be greatly appreciated. Additionally, if anyone is aware of someone that has spare parts or an ability to test/repair these keypads or the hall effect switches there contact info would be of great help.
Thank you
Nick
