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US 6,208,258 B1Granted
Circuit and method for determining whether AC mains voltage is below or above a predetermined set point
AssigneeCore Technology, Inc.
InventorJack A. Redilla
Life of this patent
Estimating the term…
Abstract
A circuit for detecting whether or not an AC voltage mains is providing an AC voltage above a predetermined point including a full wave bridge and voltage divider, a voltage detection circuit including a pair of transistors and a zener diode, an optical coupler including a light emitting diode (LED) and photo transistor, a comparator circuit for determining whether or not the AC voltage source has been below a predetermined voltage for a predetermined length of time including a comparator circuit such as a comparator or a FET.
Claims25
A circuit for detecting interruption of an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present;
- a charge circuit which charges as a function of the level detection signal;
- and
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted,
- wherein regenerative action in the level detecting circuit causes the charge circuit to discharge.
2 more elements
A circuit for detecting interruption of an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present;
- a charge circuit which charges as a function of the level detection signal;
- and
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- and
- an optoisolator between the level detection circuit and the charge circuit.
3 more elements
A circuit for detecting interruption of an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present;
- a charge circuit which charges as a function of the level detection signal;
- and
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- wherein the charge circuit is periodically discharged in response to the level detection signal under circumstances in which the AC mains has not been interrupted, and charges to at least a predetermined level under circumstances in which the AC mains has been interrupted.
2 more elements
A circuit for detecting interruption of an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present;
- a charge circuit which charges as a function of the level detection signal;
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- and
- a full wave rectifier for rectifying the AC mains, and wherein the level detection circuit comprises a zener diode coupled to the output of the full wave rectifier which breaks down every half cycle of the AC mains, provided the predefined level of the AC mains is present, to produce the level detection signal.
2 more elements
A circuit for detecting interruption of an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present;
- a charge circuit which charges as a function of the level detection signal;
- and
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted wherein the comparator output is isolated from the AC mains.
1 more element
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal with a level detection circuit indicative of when a predefined level of the AC mains is present;
- charging a charge circuit as a function of the level detection signal;
- and
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted,
- wherein regenerative action in the level detecting circuit causes the charge circuit to discharge.
2 more elements
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal with a level detection circuit indicative of when a predefined level of the AC mains is present;
- and
- charging a charge circuit as a function of the level detection signal;
- and
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- wherein the comparator output is isolated from the AC mains.
3 more elements
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal with a level detection circuit indicative of when a predefined level of the AC mains is present;
- and
- charging a charge circuit as a function of the level detection signal;
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- and
- electrically isolating the level detection circuit from the charge circuit with an optoisolator.
3 more elements
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal with a level detection circuit indicative of when a predefined level of the AC mains is present;
- and
- charging a charge circuit as a function of the level detection signal;
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- and
- periodically discharging the charge circuit in response to the level detection signal when the AC mains has not been interrupted, and charging to at least a predetermined level when the AC mains has been interrupted.
3 more elements
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal with a level detection circuit indicative of when a predefined level of the AC mains is present;
- charging a charge circuit as a function of the level detection signal;
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted;
- and
- a full wave rectification of the AC mains to produce a rectified AC mains signal, and wherein the level detection circuit comprises a zener diode coupled to the rectified AC mains signal which breaks down every half cycle of the AC mains, provided the predefined level of the AC mains is present, to produce the level detection signal.
2 more elements
A method of warning when an AC voltage source is below a predetermined set point comprising the steps of:
- inputting an AC voltage;
- essentially from the AC voltage, producing a voltage level output in accordance with the level of the AC voltage as compared to a threshold voltage;
- and
- producing an AC voltage failure output in accordance with the time the voltage level output has been below the threshold voltage,
- wherein the producing a voltage level output in accordance with the level of the AC voltage includes regenerative action.
2 more elements
A circuit for detecting interruption of an AC mains signal from an AC mains comprising:
- a level detection circuit for producing a level detection signal indicative of when a predefined level of the AC mains is present, the level detection circuit including a breakdown device;
- a charge circuit which charges as a function of the level detection signal;
- and
- a comparator for comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted,
- wherein the AC mains signal is coupled across the breakdown device and the level detection signal is based on a breakdown of the breakdown device.
2 more elements
A method for detecting interruption of an AC mains comprising:
- producing a level detection signal indicative of when a predefined level of the AC mains is present as a result of coupling the AC mains across a breakdown device;
- charging a charge circuit as a function of the level detection signal;
- and
- comparing an output of the charge circuit with a predetermined reference to produce a comparator output indicative of whether the AC mains has been interrupted.
1 more element
Dependencies are inferred from the claim text.