초록 ▼

A PWM solenolid operated valve control arrangement which substantially eliminates supply voltage dependent variability of the valve without the expense or inefficiency of a conventional voltage regulator. The coil of the solenolid valve is pulse-width-modulated in relation to the commanded output re

A PWM solenolid operated valve control arrangement which substantially eliminates supply voltage dependent variability of the valve without the expense or inefficiency of a conventional voltage regulator. The coil of the solenolid valve is pulse-width-modulated in relation to the commanded output result and the energization periods are submodulated in relation to the magnitude of the supply voltage. The effective voltage applied to the coil, and hence the operating characteristics of the solenoid valve, are thereby made substantially independent of supply voltage variations.

대표청구항 ▼

Fluid pressure control apparatus for generating a desired fluid pressure in a control chamber of a motor vehicle transmission, comprising: a source of fluid pressure; electrically energizable solenoid operated valve means adapted to alternately connect and disconnect said source and said control cha

Fluid pressure control apparatus for generating a desired fluid pressure in a control chamber of a motor vehicle transmission, comprising: a source of fluid pressure; electrically energizable solenoid operated valve means adapted to alternately connect and disconnect said source and said control chamber in accordance with such energization; a source of direct voltage including a storage battery, having a terminal voltage which varies depending on vehicle operation; control means for (1) developing a relatively low frequency PWM valve energization signal having an on-time/off-time duty cycle which if applied to the valve would produce the desired pressure in said control chamber when the terminal voltage of said source is relatively low, and (2) submodulating the on-time of said energization signal in relation to the actual terminal voltage of said source so as to effectively reduce said on-time when the actual source voltage is greater than said relatively low source voltage; and driver means for energizing the solenoid operated valve means with said source of direct voltage in accordance with the submodulated valve energization signal.