Priority relay circuit with timer
First Claim
1. A relay circuit comprising:
- a power source;
a first relay switch operable between a first and a second position;
a secondary relay switch connected to the first relay switch, the secondary relay switch being connected to the power source when the first relay switch is in the first position;
at least one secondary load device connected to the secondary relay switch;
a secondary control device connected to the secondary relay switch to operate the secondary relay switch between a first and a second position, such that power is supplied to the secondary load device only when the secondary relay switch is in the first position and the first relay switch is in the first position;
a priority load device connected to the first relay switch, the priority load device being connected to the power source when the first relay switch is in the second position;
a priority control device connected to the first relay switch, the priority control device controlling the position of the first relay switch; and
a priority timer circuit interposed between the priority control device and the first relay switch, wherein the priority timer circuit is activated by the priority control device and switches the first relay switch to the second position for a predetermined period of time, wherein the priority timer circuit energizes the priority load device and deenergizes the secondary relay switch for the predetermined time period and, upon expiration of the predetermined time period, automatically returns the first relay switch to the first position to deenergize the priority load device and energize the second relay switch.
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Accused Products
Abstract
A priority control system is disclosed for controlling multiple secondary load devices, and one priority load device. The secondary load devices can be randomly controlled at any time, except when the priority load device is activated, in which case, all secondary load devices are deactivated. The priority control system has a first relay which relays power to a plurality of secondary relays corresponding to the secondary load devices. The first relay is biased such that it normally provides power to the secondary relays. The first relay also has a priority position which is the non-biased position, for providing power to the priority load device. The first relay is activated by a priority control device which switches system power from the secondary relays to the priority load device. A priority timer circuit is provided to limit the time the first relay is in the priority position, regardless of a possible malfunction in the priority control device. This prevents a failure of the entire system in the event of a failure to the priority control or load devices.
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Citations
18 Claims
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1. A relay circuit comprising:
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a power source; a first relay switch operable between a first and a second position; a secondary relay switch connected to the first relay switch, the secondary relay switch being connected to the power source when the first relay switch is in the first position; at least one secondary load device connected to the secondary relay switch; a secondary control device connected to the secondary relay switch to operate the secondary relay switch between a first and a second position, such that power is supplied to the secondary load device only when the secondary relay switch is in the first position and the first relay switch is in the first position; a priority load device connected to the first relay switch, the priority load device being connected to the power source when the first relay switch is in the second position; a priority control device connected to the first relay switch, the priority control device controlling the position of the first relay switch; and a priority timer circuit interposed between the priority control device and the first relay switch, wherein the priority timer circuit is activated by the priority control device and switches the first relay switch to the second position for a predetermined period of time, wherein the priority timer circuit energizes the priority load device and deenergizes the secondary relay switch for the predetermined time period and, upon expiration of the predetermined time period, automatically returns the first relay switch to the first position to deenergize the priority load device and energize the second relay switch. - View Dependent Claims (2, 3)
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4. A priority control system for controlling at least one secondary load device and one priority load device comprising:
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a first relay means for relaying power to at least one secondary relay means when in a biased position, and to a priority load device when in a priority position; a priority control device connected between the first relay means and the priority load device, the priority control device operating the first relay means between the priority position and the biased position based on the status of the priority load device, wherein when the priority load device requires power, the first relay means disconnects power to the secondary relay means and connects power to the priority load device; and a priority timer means connected to the first relay means for limiting the time the first relay means is in the priority position, wherein the priority timer means returns the first relay means to the biased position after a predetermined period of time during which the priority load device requires power to return power to the secondary relay means subsequent to the predetermined period of time. - View Dependent Claims (5, 6, 7, 8)
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9. A method of preventing secondary system failure in a prioritized system when a failure occurs in a priority zone, comprising the steps of:
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relaying system power to at least one secondary relay of the secondary system through a priority relay of the priority zone; biasing the priority relay to a secondary power position thereby normally supplying power to the secondary relay; switching the priority relay from the secondary power position to a priority power position thereby supplying power to the priority zone in response to a priority control device output; monitoring the amount of time the priority relay is in the priority power position; and overriding the priority control device output when the priority relay is in the priority power position longer than a predetermined period of time, such that the priority relay returns to the secondary power position to supply power to the secondary relays after the predetermined period of time. - View Dependent Claims (10)
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11. A relay circuit comprising:
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a first relay switch connecting a power source to a priority load device and controlled by a priority control device, the first relay switch having a normally open terminal and a normally closed terminal, the priority load device being connected to the normally open terminal; a secondary relay switch connected between the first relay switch and a secondary load device and controlled by a secondary control device, the secondary relay switch being connected to the normally closed terminal of the first relay switch; and a priority timer circuit connecting the priority control device and the first relay switch, wherein the priority timer circuit is activated by the priority control device and switches the first relay switch for a predetermined period of time, thereby energizing the priority load device for a time no longer than the predetermined time period. - View Dependent Claims (12, 13)
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14. A relay circuit comprising:
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a first relay switch connecting a power source to a priority load device and controlled by a priority control device; a secondary relay switch connected between the first relay switch and a secondary load device and controlled by a secondary control device; a test switch connected between the priority control device and the first relay switch; and a priority timer circuit connecting the priority control device and the first relay switch, wherein the priority timer circuit is activated by the priority control device and switches the first relay switch for a predetermined period of time, thereby energizing the priority load device for a time no longer than the predetermined time period. - View Dependent Claims (15)
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16. A hydronic heating system including a boiler for supplying heated water to a plurality of heating zones and an indirect water heater, the system comprising:
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a plurality of heating circulators controlling the flow of hot water from the boiler to the plurality of heating zones; a plurality of thermostats positioned to monitor the heating zones; a priority circulator for controlling the flow of heated water from the boiler to the indirect water heater; an aquastat for monitoring the indirect water heater and providing a signal when the temperature of the water in the indirect water heater falls below a predetermined value; and a control circuit connected to the aquastat, the priority circulator and the plurality of heating circulators and including a timing arrangement; wherein upon receiving the signal from the aquastat, the control circuit activates the priority circulator to supply heated water to the indirect water heater and deactivates the plurality of heating circulators during activation of the priority circulator, and wherein the control circuit reactivates the plurality of heating circulators if the signal from the aquastat that activated the priority circulator endures for a time exceeding a predetermined time period.
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17. A hydronic heating system including a boiler for supplying heated water to a plurality of heating zones and an indirect water heater, the system comprising:
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a plurality of heating circulators controlling the flow of hot water from the boiler to the plurality of heating zones; a plurality of thermostats positioned to monitor the heating zones; a priority circulator for controlling the flow of heated water from the boiler to the indirect water heater; an aquastat for monitoring the indirect water heater and providing a signal when the temperature of the water in the indirect water heater falls below a predetermined value; and a control circuit connected to the aquastat, the priority circulator and the plurality of heating circulators and including a timing arrangement; wherein upon receiving the signal from the aquastat, the control circuit is operable to activate the priority circulator to supply heated water to the indirect water heater and to deactivate the plurality of heating circulators during activation of the priority circulator, and wherein the control circuit is operable to reactivate the plurality of heating circulators if the signal from the aquastat that activated the priority circulator endures for a time exceeding a predetermined time period, wherein the control circuit includes a priority relay connected to a power source and the priority circulator and a plurality of secondary relays connected to the priority relay and to corresponding heating circulators and thermostats, and wherein the timing arrangement comprises a priority timer circuit connected to the priority relay and the aquastat, wherein when the aquastat requests heated water to the indirect water heater, the priority timer circuit switches the priority relay for a predetermined time period and the priority relay activates the priority circulator and disables the plurality of secondary relays thereby providing heated water only to the indirect water heater, and when the first of either the aquastat request is satisfied or the priority timer circuit expires, the priority relay enables the plurality of secondary relays thereby permitting heated water to the heating zones based on the corresponding thermostats. - View Dependent Claims (18)
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Specification