HE-7850
This is a heavy duty magnetic contact switch (selectable normally open or normally closed). This switch is used to detect things such as doors or windows opening and closing. These are perfect for sensing something opening and closing where there can be no mechanical interference and the application demands a heavy duty robust switch (these things can be driven over by a car or truck and no damage will occur).
Normally open means the 2 wires coming off the switch are NOT connected together at all times, until the magnet gets close at which point the contacts (2 wires) connect with each other.
Normally closed means the 2 wires coming off the switch ARE connected together at all times, until the magnet gets close at which point the contacts (2 wires) break (disconnect from each other).
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