Time period configurable fluid flow control circuit

US5327473A · kind A · utility

Inventor

• Hans Weigert · Ridgewood, US

Key dates

• Filing date: Oct 30, 1992
• Grant date: Jul 5, 1994
• Expiry date: Oct 30, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/86389
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A timing circuit 10 that can be used to control the flow of fluid according to a specific time period that is allotted for each user includes a initialization circuit 30, a reset counter circuit 32, a flow time counter circuit 38, and a clock circuit 40. The timing circuit 10 accepts a DETECT* input signal, that indicates the presence of a user, and provides a DRIVE output signal that indicates when fluid shall be permitted to flow. The flow time counter circuit 38 is user configurable to provide a maximum flow time period while the DETECT* signal is active. The reset counter circuit 32 ensures that each user is provided with his or her maximum flow time period by introducing a system reset time between consecutive users and by allowing a user to remove him or her self from being detected, thus placing the DETECT* signal in an inactive state and subsequently inactivating the DRIVE signal, for certain periods of time without forfeiting any of his or her allotted maximum flow time period. The initialization circuit 30 provides the user with an initial controlled time period of fluid flow, if desired.