Float switch
Float switch, how these devices work
A float switch is a switch for turning on or off a pump according to
the water level, Ever wondered how a float switch works? wonder no more
Some pumps have a coloured lump of plastic that is connected to the
pump it stops and starts the pump, have you ever wondered how they work?
Well wonder no more. Originally float switches had a mercury capsule
inside, at the right angle the mercury rolled down to the contacts and
made electrical contact, but as mercury is dangerous it had to be
changed to something else.

Normally float switches are sealed, but this one leaked,
so we cut it open for all to see. If your float switch leaks then as they
are usually pre-wired to the pump, then there is no doubt you MUST throw
the whole pump and switch away (unless you too want to cut one open)
When it is at the correct angle the ball presses down on
the arm, which in turn via the lever presses the button on the micro
switch, breaking a circuit and so the pump stops. (you thought i was going
to say starts)
When the float is not at the right angle the ball rolls
towards the other end releasing the button on the micro switch and so the
pump starts.
You may also want to see
this
see here
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