try again, as Adrian's store 404's on the direct link to the product

[web/altusmetrum] / FAQs / active-switch.mdwn

# What do you mean by 'active switch' in the manual?

The only active switch we're aware of is the Featherweight Magnetic Switch
sold by [Featherweight Altimeters](https://www.featherweightaltimeters.com)

These need three connections .. a ground, an input, and an output.  Of
the two switch screw terminals on Altus Metrum products, one is
connected to the + side of the battery terminal and is the input to such
a switch, the other connects to the output of the switch.  Ground can be
found on another screw terminal on TeleMega and EasyMega, there's an
extra explicit hole you can solder a wire to on TeleMetrum, and all of
our products have grounded mounting screw holes.

For a typical, simple, mechanical switch .. you can ignore all this and
just connect the two "switch" screw terminals.