The solenoid valve controls the expansion of one cylinder
To solenoid valve power, just switch the A and B mouth of the original ventilation state, that is, A and B reverse inlet and exhaust gas, so the cylinder also followed the reverse movement.
The A and B are always one intake, one vent to the cylinder, and the cylinder is only extended and retracted in two states.
The simplest way is to solenoid valve solenoid head power and power off, the cylinder will stretch or shrink.
Only one solenoid valve is needed to control the expansion of any cylinder.
