摘要 |
<p>Discloses a pneumatic controller having a proportional band altering unit, a proportional plus integral operation unit, a comparator and a manual-automatic transfer means, wherein the proportional band altering unit is combined with the proportional plus integral operation unit to provide a proportional band altering mechanism which limits input to prevent output of the comparator from being saturated whereby to enable the pneumatic controller to perform the transfer between the manual and automatic modes in a balanceless and bumpless manner.</p> |