The confusing arrangement of reed switches inside a float switch
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The float ball usually stays at the bottom, resulting in an open circuit and no signal; when the float ball rises, the circuit is closed and an alarm is triggered. The problem is that after taking this switch apart, I found a magnet placed right next to the reed switch – what is the purpose of that? It’s quite strange. Should I change it from an normally open switch to a normally closed one? I’m still worried that the magnetism isn’t strong enough, so I add another one – but that’s not right either; won’t it be constantly affected by the magnet?
I would appreciate it if the expert could explain why a small magnet is buried beside it – is there any special purpose for that?
This post was last edited by feng*aosa on 2021-1-28 21:33. That small magnet serves to hold things in place. The strength of the small magnet is not sufficient to attract the reed switch, but it is enough to keep it in the attracted state without it releasing. Otherwise, the external magnetic field causes the reed switch to close at its location; once past the reed switch, it closes again. The direction of the small magnet, in combination with the external magnetic field, results in a position where the poles at both ends of the reed switch are aligned, causing the reed switch to open.