This is a rough guide to making a sip/puff switch
operate standard switch equipment.
Sip/puff switches (also known as low pressure/vacuum or suck/puff switches)
can be obtained from www.rswww.com
for around £23 each with 1m of PVC tube (code 317-443). You attach a tube
to the front or the back of the switch (in the middle), to give control via either
sip to activate, or puff to activate. They are in effect, simple on/off switches,
and require no external power. To get both actions using one tube, you will need to mount two switches one on top of the other. Update: An alternative worth looking at is the Herga Differential Pressure Sensor. Link via Gavin Tan at SpecialEffect.
If you're an absolute beginner, we strongly recommend that you follow "The
Basic Soldering Guide" - by Alan Winstanley.
To see sip/puff switches in action, see Mark BB's Nintendo
64 and Playstation
"Pneumatic switches which are vented both sides of a diaphragm and can thus
be used in either pressure, vacuum or differential modes. The single pole contacts
remain in the normally open position until the operational differential pressure
is reached. As the contact pressure is dependent on the air pressure, the switch
rating will be reduced when used at the minimum operating pressures."
1. What you will need:
1x low pressure/vacuum switch (with PVC connecting tube - supplied)
1x 3.5mm mono plug
1x Mounting system to bring to chin
Soldering iron (15 to 30 Watt power); thin solder; soldering flux; desoldering
braid; speaker wire (2 wires).
Knife or wire strippers. Tools to make mounting system.
2. Wire and test:
Connect your speaker wire from the 3.5mm plug to the sip/puff switch.
Connect an appropriate length of PVC tube to the switch and test.
3. Mount and tidy.
Find a way to position the switch near to the person's mouth safely. Try
to keep your wiring as tidy as possible.
Image pictured is of Mark
Bosanquet-Bryant's sip/puff Playstation controller.
D.I.Y. Text PUBLIC DOMAIN 2003 - www.OneSwitch.org.uk