Abstract Control apparatus featuring a condition sensor, a first relay responsive to a signal from the condition sensor, the first relay being in a first state in the absence of a signal from the condition sensor and being switched to a second state in response to a signal from the condition sensor, a control relay adapted to be switched between first and second states, circuitry responsive to an operation request for switching the control relay from the first state to the second state after a time interval, and clamping circuitry operative in response to the detection of the first relay in its second state during the time interval to clamp the first relay in the second state and the control relay in the first state, overriding the influence of the condition sensor on the first relay.
Control apparatus for a burner comprising a flame sensor, a first relay responsive to a signal from said flame sensor, said first relay being in a first state in the absence of a signal from said flame sensor and being switched to a second state in response to a signal from said flame sensor, a control relay adapted to be switched between first and second states, time interval providing circuitry responsive to an operation request for switching said control relay from said first state to said second state after a time interval, and clamping circuitry responsive to the detection of said first relay in its second state during said time interval to clamp said first relay in said second state and said control relay in said first state, overriding the influence of said flame sensor on said first relay.
Claim 2
Dependent Claim
139 words
Control apparatus for a burner comprising a flame sensor, a first relay responsive to a signal from said flame sensor, said first relay being in a first state in the absence of a signal from said flame sensor and being switched to a second state in response to a signal from said flame sensor, a control relay adapted to be switched between first and second states, time interval providing circuitry responsive to an operation request for switching said control relay from said first state to said second state after a time interval, and clamping circuitry responsive to the detection of said first relay in its second state during said time interval to clamp said first relay in said second state and said control relay in said first state, overriding the influence of said flame sensor on said first relay.
Claim 3
Dependent Claim
57 words
The control apparatus of claim 1 wherein said control relay includes an operating coil connected in series with a normally open contact of said control relay across a power source, and further including a normally open contact controlled by said first relay connected in series between said control relay coil and the input to said first relay.