| 摘要 |
<p>A discharge pressure value is smoothly brought close to a set pressure value, and fluctuation of the discharge pressure value reaching the set pressure value is reduced. When a difference C between the discharge pressure value P (B) of a pneumatic pressure regulator and a set pressure value A is relatively great, a solenoid valve (31) is driven by a pulse width modulation signal D. Therefore, a high-speed input/output response (change characteristics of a pressure detection signal B with respect to a set pressure signal A) is retained. When the discharge pressure value P is close to the set pressure value Q, the solenoid valve (31) is driven by a pulse frequency modulation signal J. Therefore, an excessive change quantity, that is, so-called 'over-shoot', becomes small, and the change of the discharge pressure value P reaching the set pressure value Q, that is, so-called 'ripple', can be eliminated.</p> |
