Automatic control for an adjustable member
First Claim
1. A switching arrangement for control of an adjustable member comprising:
- a light sensitive switching means for generating an enabling signal in response to a sensed light value beyond a predetermined threshold level;
delay circuit means for receiving the enabling signal from the light sensitive switching means and providing an actuating signal a predetermined delay period after receipt of the enabling signal;
a control circuit for control of the adjustable member, said control circuit receiving said actuating signal from the delay circuit means to actuate the adjustable member; and
a switching circuit, responsive to the actuating signal, for establishing an input signal to the delay circuit means which causes the delay circuit means to transmit a deactuating signal to the control circuit a predetermined actuation period after receipt of the actuating signal by the control circuit.
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Accused Products
Abstract
A switching arrangement for the control of an adjustable member such as a valve includes a light sensitive switch. Detection of a particular light value enables a frequency divider to transmit an opening pulse to a valve control circuit a predetermined delay period after the detection of such light value. The frequency of an output signal of a pulse generator is varied in response to the opening pulse and the frequency divider transmits a closing pulse to the control circuit after a second predetermined time period of different duration from the delay period. In one disclosed embodiment, control of the frequency divider is responsive to moisture content of soil as well as ambient light level for application in automatic sprinkler systems.
11 Citations
13 Claims
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1. A switching arrangement for control of an adjustable member comprising:
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a light sensitive switching means for generating an enabling signal in response to a sensed light value beyond a predetermined threshold level; delay circuit means for receiving the enabling signal from the light sensitive switching means and providing an actuating signal a predetermined delay period after receipt of the enabling signal; a control circuit for control of the adjustable member, said control circuit receiving said actuating signal from the delay circuit means to actuate the adjustable member; and a switching circuit, responsive to the actuating signal, for establishing an input signal to the delay circuit means which causes the delay circuit means to transmit a deactuating signal to the control circuit a predetermined actuation period after receipt of the actuating signal by the control circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A switching arrangement for control of a valve in an automatic sprinkling system comprising:
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a light sensitive switching means for delivering an enabling signal at dusk; a delay circuit means for receiving an enabling signal from the light sensitive switching means and delivering an actuating signal a predetermined delay period after receipt of the enabling signal; a control circuit for control of the valve, said control circuit receiving said actuating signal from the delay circuit means to open the valve; and a switching circuit, responsive to the actuating signal, for establishing an input signal to the delay circuit means which causes the delay circuit means to transmit a deactuating signal to the control circuit to close the valve a predetermined actuation period after receipt of the actuating signal by the control circuit. - View Dependent Claims (11, 12)
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13. A switching arrangement as defined in clam 12, wherein the moisture sensing means is an evaporation cup disposed at or near ground level in the area swept by the sprinkling system and wherein the evaporating cup receives sprinkling or rain water and the moisture sensing means delivers an inhibit signal as long as the water has not yet evaporated from the cup.
Specification