AUTOMATIC WATER SUPPLY SYSTEM

• US 3,575,640 A
• Filed: 11/20/1968
• Issued: 04/20/1971
• Est. Priority Date: 11/27/1967
• Status: Expired due to Term

• Current Assignee: Ishikawa Tadayuki
• Original Assignee: Ishikawa Tadayuki
• Inventors: ISHIKAWA TADAYUKI
• Application Number:
  US04/777,253
• Time in Patent Office: 881 Days
• US Class Current: 361/181
• CPC Class Codes: H03B 2200/0034 including a buffer amplifier
• CPC Class Codes: H03B 2200/0066 Amplitude or AM detection
• CPC Class Codes: H03B 5/1203 the amplifier being a single transistor
• CPC Class Codes: H03B 5/1231 the amplifier comprising one or more bipolar transistors
• CPC Class Codes: H03B 5/1243 the means comprising voltage variable capacitance diodes
• CPC Class Codes: H03B 5/1296 the feedback circuit comprising a transformer
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2017/9606 using one electrode only per touch switch

Abstract

An automatic water supply control system for a toilet facility, wash basin or the like which features a capacity-sensitive antenna positioned to sense the approach of a user and cause a valve actuator signal to be produced, coupled with a circuit for compensating for slow changes in antenna capacity caused by changes in ambient conditions, such as humidity. The system includes timing and delay circuitry which permit the system to allow for minor movements of the user adjacent to the facility and to shut off after a predetermined period of operation.

Claims

1. An automatic water supply control system for a toilet facility or the like comprising:

a. a detector circuit including a capacity-sensitive antenna positioned to respond to the approach of a user of the facility and means responsive to a change in antenna capacity to produce an output signal;

b. a compensator circuit coupled to said detector circuit and including means sensitive to the rate of change of said output signal and operable in response to rates of change below a predetermined rate to cancel said change and maintain said output signal at a predetermined level;

c. water valve control means;

d. means for actuating said valve control means including circuit means operable in response to output signal changes not cancelled by said compensating circuit to produce a valve actuating signal; and

e. means responsive to said valve actuating signal for deactivating said compensator circuit.

2. The system of claim 1 further including delay means coupled to said deactivating means to maintain the same in its deactivating condition for a predetermined period following termination of said valve actuating signal.

3. The system of claim 1 further including timing means triggered by said valve actuating signal and operable after a predetermined period of delay to reactivate said compensator circuit.

4. The system of claim 3 further including delay means coupled to said deactivating means to maintain the same in its deactivating condition for a predetermined period following termination of said valve actuating signal.

5. The system of claim 4 wherein said deactivating means comprises a relay having a normally closed contact coupled between said detector and compensator circuits, said relay being energized by said actuator signal to open said contact.

6. The system of claim 5 wherein said reactivating means comprises means responsive to termination of said valve actuating signal to deenergize said relay and a delay circuit coupled to said relay to delay deenergization thereof for said predetermined period.

7. The system of claim 5 wherein said reactivating means comprises an RC circuit charged toward a predetermined voltage level in response to said activating signal, and circuit means coupled to the detector circuit and operable when said RC circuit becomes charged to said voltage level to produce a detector circuit output signal corresponding to the absence of a user of said facility, thereby deenergizing said relay and reactivating said compensator circuit.

8. The system of claim 3 wherein said compensator circuit includes a capacitor charged to a level determined by the capacity of said antenna for its ambient conditions, and means for maintaining said level of charge during the period of deactivation of said compensator circuit.