Voltage detecting circuit
AssigneeHon Hai Precision Industry Co., Ltd.
InventorTing-Kai Wang
Life of this patent
Estimating the term…
Abstract
A power supply voltage detecting circuit includes a voltage regulating circuit, a comparative circuit, a timer circuit, and a display circuit. The voltage regulating circuit provides a stable reference voltage to the comparative circuit. The comparative circuit compares the reference voltage with the voltage from the power supply. The comparative circuit is electrically connected to the display circuit via the timer circuit. The display circuit includes light emitting diodes for revealing a status of the voltage from the power supply. The timer circuit causes the display circuit to keep a light on when there has been an occurrence of abnormal voltage from the power supply until an operator resets it.
Claims13
A voltage detecting circuit, comprising:
- a comparative circuit for comparing a reference voltage with a voltage from a power supply;
- a voltage regulating circuit for providing the reference voltage to the comparative circuit;
- a display circuit for revealing a status of the voltage from the power supply;
- and
- a timer circuit electrically connected between the comparative circuit and the display circuit to cause the display circuit to maintain a status display when there has been an occurrence of abnormal voltage from the power supply, wherein the comparative circuit comprises a first operational amplifier and a second operational amplifier, both a negative input of the first operational amplifier and a positive input of the second operational amplifier receiving the reference voltage;
- a positive input of the first operational amplifier receiving the voltage from the power supply via a first resistor;
- a negative input of the second operational amplifier connected in series with a second resistor connected to the positive input of the first operational amplifier, and grounded via a third resistor.
A voltage detecting circuit for detecting and indicating when voltage of a DC power supply is in an abnormal state, the voltage detecting circuit comprising:
- a voltage comparator formed by a first operational amplifier and a second operational amplifier, a positive input of the first operational amplifier connected to the voltage from a power supply via a first resistor;
- a negative input of the second operational amplifier in series with a second resistor connected to the positive input of the first operational amplifier;
- the negative input of the second operational amplifier grounded via a third resistor as well;
- a Zener shunt regulator for generating a stable reference voltage for the voltage comparator, an anode of the regulator grounded, a cathode of the regulator connected to the voltage from the power supply, both a negative input of the first operational amplifier and a positive input of the second operational amplifier connected to the stable reference voltage;
- a display circuit for revealing a states of the voltage from the power supply;
- and
- a timer circuit electrically connected between the voltage comparator and the display circuit to cause the display circuit to maintain a status display when there has been an occurrence of abnormal voltage from the power supply.
A circuit for detecting voltage of a power supply, comprising:
- a voltage regulating circuit for providing a reference voltage to be in comparison therewith;
- a comparative circuit electrically connectable with said voltage regulating circuit and with a power supply so as to input said reference voltage from said voltage regulating circuit and a power voltage to be detected from said power supply for comparison, said comparative circuit comprising a first comparator and a second comparator to electrically connect with said voltage regulating circuit for respectively retrieving two different voltage inputs out of said power voltage so as to generate at least three different comparative outputs, a positive input of said first comparator electrically connectable with said power supply via a first resistor;
- a negative input of said second comparator in series with a second resistor electrically connectable to said positive input of said first comparator;
- said negative input of said second comparator grounded via a third resistor;
- and
- a display circuit electrically connectable with said comparative circuit for indicating a corresponding status of said power voltage of said power supply based on said at least three comparative outputs of said comparative circuit.
Dependencies are inferred from the claim text.