Claims
- 1. A delay circuit for automatically preventing the permanent closure of a fluid solenoid valve positioned in a fluid line in the event of a momentary loss or drop in input voltage of less than a predetermined time interval and for manually restoring operation of the solenoid valve subsequent to an input voltage interruption which exceeds the predetermined time interval, said circuit comprising:
- switching means including a relay and a switch contact, said relay maintaining said switch contact in a first position when the input voltage interruption occurs which is less than the predetermined time interval and moving said switch contact to a second position when the input voltage interruption occurs which is greater than the predetermined time interval;
- delay means operatively coupled to the relay of said switching means for maintaining said switch contact in said first position when the input voltage interruption occurs which is less than the predetermined time interval;
- a fluid solenoid valve being operatively coupled to the input voltage when the switch contact is in said first position to maintain said valve open to permit the flow through the fluid line, said fluid valve being disconnected from the input voltage when the switch contact is in the said second position to close said fluid valve and discontinue flow in the fluid line; and
- a manually resettable switch operatively connected to said first position of said switch contact, said resettable switch being required to be actuated to supply the input voltage to said relay subsequent to the input voltage interruption which exceeded said predetermined time interval and to restoration of the input voltage for transferring said switch contact from said second position back to said first position to reopen said valve to permit flow through the fluid line.
- 2. The delay circuit as claimed in claim 1, wherein said delay means includes a capacitor coupled to said relay, said capacitor being fully charged in normal operation to maintain said relay energized and said switch contact in said first position, said capacitor discharging completely when the input voltage interruption occurs which is greater than said predetermined time interval thus moving said switch contact from said first position to said second position.
- 3. The delay circuit as claimed in claim 2, further comprising warning indication means operatively connected to said switch contact in said second position for indicating an input voltage interruption has occurred which exceeds said pre-determined time interval once the input voltage has been restored.
- 4. The delay circuit as claimed in claim 3, wherein said warning indication means includes an audio means.
- 5. The delay circuit as claimed in claim 4, wherein said indication means includes a light means.
- 6. The delay circuit as claimed in claim 4, wherein said warning indication means includes an audio means and a light means to provide both audio and visual indications.
Parent Case Info
This is a continuation, of application Ser. No. 716,085 filed Aug. 20, 1976, now abandoned.
US Referenced Citations (9)
Continuations (1)
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Number |
Date |
Country |
Parent |
716085 |
Aug 1976 |
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