3. Design and draw a circuit using the cascade system to operate two
cylinders (A and B) which, on the operation of a start valve, produces the
sequence A – B + B – A+. The cylinders should park in the positions
B – A + when the start switch is in the ‘off’ position.
4. Modify the circuit designed for question 3 to provide an emergency stop
which will park both cylinders in the extended position (i.e. A + B +).
5. Modify the circuit designed for question 3 to provide a fail safe. The fail
safe should:
(a) act in the event of a reduced pressure at inlet to the group selecting
valve
(b) park the cylinders in the retracted position.