Automatic voltage selector control circuit for test sets with tap selectable line input transformers
First Claim
1. An input adaptable electrical device comprising:
- an input for receiving an input voltage from an unidentified power source;
a main transformer having a primary winding and a secondary winding, the primary winding of the main transformer connected to receive the input voltage from the input, the primary winding of the main transformer having first, second and third transformer taps that allow the main transformer to be configured in a first configuration or a second configuration;
a circuit breaker connected between the input and the primary winding of the main transformer, when ‘
open’
the circuit breaker prevents the input voltage from being provided to the primary winding of the main transformer and when ‘
closed’
the circuit breaker allows the input voltage to be provided to the primary winding of the main transformer; and
an automatic input voltage detection circuit connected to monitor the input voltage provided by the unidentified power source, wherein the automatic input voltage detection circuit identifies the power source based on the monitored input voltage, and selects the first configuration or the second configuration of the main transformer based on the identification of the power source, the automatic input voltage detection circuit including;
a step-down transformer having a primary winding and a secondary winding, the primary winding connected to the input to receive the input voltage;
a first relay connected to the second tap of the main transformer, the first relay being energized to selectively configure the main transformer in the first configuration;
a second relay connected to the third tap of the main transformer, the second relay being energized to selectively configure the main transformer in the second configuration; and
an auto-volt comparator circuit connected to monitor a stepped-down voltage provided by the secondary winding of the step-down transformer that is representative of the input power, wherein the auto-volt comparator circuit identifies the power source based on the stepped-down voltage and in response selectively energizes either the first relay or the second relay to configure the main transformer.
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Accused Products
Abstract
An input adaptable electrical test set provides for the automatic detection of the power source connected to the test set, as well as automatic configuration of the test set to accommodate the identified power source. Prior to identification of the power source, a circuit breaker isolates a main transformer associated with the test set from receiving power from the power source. The main transformer includes a primary winding and a secondary winding, the primary winding having first, second and third tap positions that allows the transformer to be configured in one of two states depending on the power source connected to the test set. An automatic input voltage detection circuit monitors the input voltage provided by the unidentified power source and identifies the power source based on the monitored voltage. Based on the identification of the power source, the automatic input voltage detection circuit selects the configuration of the main transformer and the circuit breaker is closed to allow power from the power source to be supplied to the main transformer.
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Citations
9 Claims
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1. An input adaptable electrical device comprising:
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an input for receiving an input voltage from an unidentified power source; a main transformer having a primary winding and a secondary winding, the primary winding of the main transformer connected to receive the input voltage from the input, the primary winding of the main transformer having first, second and third transformer taps that allow the main transformer to be configured in a first configuration or a second configuration; a circuit breaker connected between the input and the primary winding of the main transformer, when ‘
open’
the circuit breaker prevents the input voltage from being provided to the primary winding of the main transformer and when ‘
closed’
the circuit breaker allows the input voltage to be provided to the primary winding of the main transformer; andan automatic input voltage detection circuit connected to monitor the input voltage provided by the unidentified power source, wherein the automatic input voltage detection circuit identifies the power source based on the monitored input voltage, and selects the first configuration or the second configuration of the main transformer based on the identification of the power source, the automatic input voltage detection circuit including; a step-down transformer having a primary winding and a secondary winding, the primary winding connected to the input to receive the input voltage; a first relay connected to the second tap of the main transformer, the first relay being energized to selectively configure the main transformer in the first configuration; a second relay connected to the third tap of the main transformer, the second relay being energized to selectively configure the main transformer in the second configuration; and an auto-volt comparator circuit connected to monitor a stepped-down voltage provided by the secondary winding of the step-down transformer that is representative of the input power, wherein the auto-volt comparator circuit identifies the power source based on the stepped-down voltage and in response selectively energizes either the first relay or the second relay to configure the main transformer. - View Dependent Claims (2, 3, 4, 5)
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6. An input adaptable test set comprising:
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an input for receiving an unknown input voltage; a main transformer having a primary winding and a secondary winding, the primary winding connected to the input through an input circuit breaker that when ‘
open’
prevents application of the unknown input voltage to the primary winding and when ‘
closed’
allows application of the unknown input voltage to the primary winding, the primary winding have a first tap, a second tap and third tap that allows the main transformer to be configured in a first state or a second state;a first relay connected to the second tap of the transformer, wherein when energized the first relay connects the main transformer in the first state; a second relay connected to the third tap of the transformer, wherein when energized the second relay connects the main transformer in the second state; a step-down transformer having a primary winding and a secondary winding, the primary winding connected to the input and configured to step down the unknown input voltage at the secondary winding; and an auto-volt comparator circuit connected to the secondary winding of the step-down transformer that identifies the power source based on a stepped-down voltage provided by the step-down transformer, wherein the comparator circuit selectively energizes either the first relay or the second relay to configure the main transformer based on the identification of the power source. - View Dependent Claims (7, 8, 9)
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Specification