I got into pneumatics because I thought of it as a way to get around the 3
input 3 output limits of the RCX.
My first goal with pneumatics was to build a gate to allow me to use boolean
logic and state machine design techniques to build advanced pneumatic robotic
controls.
Embedded inside the structure is a pneumatic switch. There are two inputs
into the OR gate. Each input controls the pistons in the OR gate. If either
piston is expanded, the pneumatic switch is thrown one way. If both pistons are
contracted, the switch is thrown the other way.
The gate can be configured as either an AND or an OR gate, depending on how
the tubing is hooked to the pistons and valves. With this pnematic hookup
configuration, a boolean NOT can be achieved by swapping the two connections to
a given piston, or the outputs of a switch.
I used three of theese gates to produce an XOR gate to do binary pneumatic
arithmetic in my pneumADDic
adding machine invention.
MLCAD
building description in a ZIP archive
OR gate
configuration
AND gate
configuration
