I'm curious about keypads in regards to voltage. I have searched, and not found much related to this topic. It seems to me that keypads can take nearly any voltage so long as the voltage supplied is greater than the voltage dropped by the keypad. This wouldn't make sense though since most keypads list themselves as 12VDC. Can a keypad labeled for a higher or lower voltage take a higher or lower voltage? For example, supplying a keypad labeled 12VDC with 5VDC.
Keypads are strictly mechanical, with the connection being made between two pieces of metal, carbon, and/or conductive rubber. The voltage rating given in the specs is the maximum (greater voltages may result in arcing), with the minimum depending on both the contact resistance and available current from the keypad driver.