Delay circuit

Claim 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.