ADAPTING BATTERY-POWERED TOYS
Almost any gadget which is powered by a battery or several batteries can be
adapted so that it can be turned on by pressing a commercial switch. It really
is a very simple operation.
A battery-powered toy consists of three parts: the battery, the toy, and its
switch. Think of a torch. Figure (i) is a torch in diagram form.
If you were to 'break' the circuit anywhere, by cutting the wire, or by pulling
the batteries away, or by switching off the switch, everything stops.
Join it up again, or add a loop of wire a hundred yards long with a switch
on the end of it, and the light comes on again. Figure (ii).
Now, if you have a student who has difficulty making fine movements with her
hands, how are you going to get her to turn on the torch? You can adapt it so
that the torch can lie in front of her, and she can press a large switch with
a gross movement of her hand to work the light.
It is a very simple operation. It is a matter of 'breaking' the circuit somewhere
inside the torch, then joining a length of wire to it so that a distant switch
can be connected to it.
One of the easiest places to do this is where the positive end of the battery
touches a terminal. If you work from here you won't have to get right inside the
toy [this only works for the most simple of toys - see the D.I.Y. Tumbler
example for a more complicated device].