CN101470172A - CMOS battery voltage test device - Google Patents

Abstract

A voltage test device for CMOS batteries comprises a voltage generation circuit, a voltage comparer and a light emitting diode, wherein the voltage generation circuit is connected with a power supply; one input end of the voltage comparer is connected with the anode of a CMOS battery and another input end is connected with the voltage generation circuit via a first divider resistor and is grounded via a second divider resistor, the output end is connected with the anode of the light emitting diode, the cathode of the light emitting diode is grounded, the cathode of the CMOS battery is grounded; the voltage generation circuit generates a voltage which is divided via the first and the second divider resistors, the another input end of the voltage comparer generates a comparison voltage, the voltage comparer compares the voltages at two input ends to output high potential or low potential signals at the output end, to drive the light emitting diode to be communicated or stopped, thereby indicating that the current voltage of the CMOS battery is higher or lower than the comparison voltage. The voltage test device for CMOS batteries has simple theory and simple application.

Description

CMOS battery voltage test device

technical field

The invention relates to a battery voltage testing device, in particular to a testing device for testing the voltage of a CMOS battery.

Background technique

As we all know, the CMOS chip in the computer is a readable and writable RAM chip on the computer motherboard, which is mainly used to save the hardware configuration of the current system and the settings of certain parameters by the operator. CMOS battery power supply, so the information on the CMOS chip will not be lost whether it is in the shutdown state or the system is powered off. The total voltage of the CMOS battery is 3V. Usually, when its voltage is consumed to less than 2V, it is difficult to Continue to supply power to the CMOS chip. When the power supply of the CMOS chip is insufficient, the computer will have a series of problems such as incorrect information on certain parameters, or slow running speed. When the power supply for the CMOS chip is about to be insufficient, the above-mentioned problem can be solved by replacing the CMOS battery in time.

Contents of the invention

In view of the above, it is necessary to provide a CMOS battery voltage testing device, which can display the CMOS battery voltage after testing.

A CMOS battery voltage testing device, comprising a voltage generating circuit, a comparative amplifier and a light-emitting diode, the voltage generating circuit is connected to a power supply, one input of the comparative amplifier is connected to the positive pole of a CMOS battery, and the other input The end is connected to the voltage generating circuit through a first voltage dividing resistor, and grounded through a second voltage dividing resistor, the output end is connected to the anode of the light-emitting diode, the cathode of the light-emitting diode is grounded, and the negative pole of the CMOS battery is grounded. The voltage generation circuit generates a voltage greater than the total voltage of the CMOS battery, and generates a comparison voltage at the other input terminal of the comparison amplifier through the voltage division of the first and second voltage division resistors, and the comparison amplifier passes Comparing the voltages of its two input terminals, outputting a high-level or low-level signal at its output terminal to drive the light-emitting diode to be turned on or off, to indicate that the current voltage of the CMOS battery is greater than or less than the comparison voltage.

A CMOS battery voltage testing device, comprising a voltage generating circuit, a plurality of comparative amplifiers, a plurality of light emitting diodes and a plurality of first voltage dividing resistors, the voltage generating circuit is connected to a power supply, and the first resistor is connected in series to the voltage generating Between the circuit and the ground, one input end of each comparative amplifier is connected to the positive pole of a CMOS battery, the other input end is respectively connected to the connection node between the first voltage dividing resistors, and the output end is respectively connected to a corresponding light-emitting diode. The anode of the diode, the cathode of each light-emitting diode are grounded, the negative electrode of the CMOS battery is grounded, the voltage generating circuit generates a voltage greater than the total voltage of the CMOS battery, and the voltage is divided by the first voltage dividing resistor, respectively at each The other input terminal of a comparative amplifier generates a comparative voltage, and each comparative amplifier outputs a high-level or low-level signal at its output terminal by comparing the voltages of its two input terminals, so as to drive the corresponding light-emitting diode to be turned on or off, so as to Respectively indicate that the current voltage of the CMOS battery is greater than or less than the corresponding comparison voltage.

The CMOS battery voltage testing device uses a comparison amplifier to compare the current voltage of the CMOS battery with the comparison voltage, so that the comparison amplifier outputs a high level to drive the light-emitting diode to emit light, or outputs a low level, and the diode does not emit light, so that the user knows that the CMOS The current voltage of the battery is greater than or less than the comparison voltage, the principle is simple and easy to implement.

Description of drawings

Below in conjunction with accompanying drawing and preferred embodiment the present invention is described in further detail:

FIG. 1 is a circuit diagram of a preferred embodiment of a CMOS battery voltage testing device of the present invention.

Detailed ways

Please refer to FIG. 1 , the CMOS battery voltage testing device of the present invention includes a voltage generating circuit 10 , a testing circuit 20 and an indicating circuit 30 .

The voltage generation circuit 10 includes an adjustable shunt reference source T of model TL431, two voltage divider resistors R1 and R2 with the same resistance value, a current limiting resistor R3 and a capacitor C1, and the voltage divider resistors R1 and R2 are connected to each other. One end of the adjustable shunt reference source T is connected to the reference end, and the other end of the voltage dividing resistors R1 and R2 are respectively connected to the cathode and anode of the adjustable shunt reference source T, and the cathode of the adjustable shunt reference source T is connected to One end of the current-limiting resistor R3 and the capacitor C1, the other end of the current-limiting resistor R3 is connected to a 12V power supply, and grounded through a capacitor C2, and the other end of the capacitor C1 is grounded to the adjustable shunt reference The anode of source T is grounded.

The test circuit 20 includes comparative amplifiers U1, U2, U3, U4 and voltage dividing resistors R4, R5, R6, R7, R8, and the positive input ends of the comparative amplifiers U1, U2, U3, U4 are connected to each other. The node is connected to the positive pole of a CMOS battery J through a resistor R9 and a switch S connected in series, and the inverting input terminal of the comparative amplifier U1 is connected to the cathode of the adjustable shunt reference source T through the voltage dividing resistor R4, so The voltage dividing resistors R5, R6, and R7 are respectively connected between the inverting input terminals of the comparative amplifier U1 and U2, between the inverting input terminals of U2 and U3, and between the inverting input terminals of U3 and U4. The inverting input terminal of the comparison amplifier U4 is also grounded through the voltage dividing resistor R8.

The indicator circuit 30 includes light emitting diodes D1, D2, D3, D4, resistors R10, R11, R12, R13 and a 4Pin connector 32, and one end of the resistors R10, R11, R12, R13 is connected to the comparative amplifiers U1, U2 respectively. , the output ends of U3, U4 are connected, and the other ends are respectively connected with the anodes of the light-emitting diodes D1, D2, D3, D4, and the anodes of the light-emitting diodes D1, D2, D3, D4 are respectively connected to the connector 32 A corresponding pin, the connector 32 is used to connect the basic input output system (BIOS) of the computer, and the cathodes of the light emitting diodes D1, D2, D3, D4 are grounded.

When the computer is turned on and the switch S is closed, the CMOS battery voltage testing device starts to work. At this time, the CMOS battery J outputs a voltage to the positive input terminals of the comparison amplifiers U1, U2, U3, and U4, Because the resistance values of the voltage dividing resistors R1 and R2 are equal, the cathode of the adjustable shunt reference source T is used as the output terminal of the voltage generating circuit 10 to output a stable 5V voltage to the testing circuit 20, so The 5V voltage is divided by the voltage dividing resistors R4, R5, R6, R7, R8 to generate 3V, 2.6V, 2.3V and 2V voltages respectively to the reverse input of the comparative amplifiers U1, U2, U3, U4 After comparing the voltage of the CMOS battery J with the voltages of 3V, 2.6V, 2.3V and 2V respectively, the output terminals of the comparison amplifiers U1, U2, U3 and U4 output a high level or a low level For example, when the voltage of the CMOS battery J is between 2V and 2.3V, such as 2.2V, the voltages of the inverting input terminals of the comparative amplifiers U1, U2, and U3 are all greater than the voltages of their positive input terminals, that is, 2.2V V voltage, the voltage of the positive input terminal of the operational amplifier U4 is greater than the voltage of its reverse input terminal, the output terminal of the operational amplifier U4 outputs a high level, and the light emitting diode D4 is made to emit light through the resistor R13, and the user immediately Through the only light-emitting diode D4 on the main board, it is known that the current voltage of the CMOS battery J is between 2V and 2.3V, that is, the voltage of the CMOS battery J is about to be less than 2V, and cannot continue to supply power to the CMOS chip, and the user needs to replace it in time For a new CMOS battery, and so on, when the voltage of the CMOS battery J is between 2.3 and 2.6V, the LEDs D3 and D4 emit light, and the LEDs D1 and D2 do not emit light. The voltages of the output terminals of the comparative amplifiers U1, U2, U3, and U4 are transmitted to the BIOS through the connector 32, and the current voltage of the CMOS battery J can also be displayed to the user through the computer monitor through the programming of the BIOS. .

In this embodiment, it is also possible to increase or decrease the number of comparative amplifiers and corresponding voltage dividing resistors and light-emitting diodes in the test circuit 20 according to actual needs. For example, when the user needs to know the current voltage of the CMOS battery in more detail, The number of comparison amplifiers, corresponding voltage dividing resistors and light emitting diodes can be increased, so that the test circuit 20 can divide a smaller interval between the 2V and 3V voltages.

Claims (9)

1. [claim 1] a kind of CMOS battery voltage test device, comprise a voltage generation circuit, one comparison amplifier and a light emitting diode, described voltage generation circuit connects a power supply, one input end of described comparison amplifier is connected in the positive pole of a CMOS battery, another input end links to each other with described voltage generation circuit by one first divider resistance, and by one second divider resistance ground connection, output terminal connects the anode of described light emitting diode, the plus earth of light emitting diode, the minus earth of described CMOS battery, described voltage generation circuit produces the voltage greater than CMOS battery total voltage, through described first, the dividing potential drop of second divider resistance, another input end at described comparison amplifier produces a comparative voltage, described comparison amplifier is by comparing the voltage of its two input end, at its output terminal output high level or low level signal, order about described light emitting diode conducting or end, be greater than or less than comparative voltage with the current voltage of indication CMOS battery.
2. [claim 2] CMOS battery voltage test device as claimed in claim 1, it is characterized in that: described voltage generation circuit comprises an adjustable shunting reference source, the negative electrode of described adjustable shunting reference source connects described power supply by a current-limiting resistance, plus earth, the reference edge of described adjustable shunting reference source connects an end of one the 3rd, 1 the 4th divider resistance, the other end of described the 3rd divider resistance connects the negative electrode of described adjustable shunting reference source, and the other end of the 4th divider resistance connects the anode of adjustable shunting reference source.
3. [claim 3] CMOS battery voltage test device as claimed in claim 1, it is characterized in that: the end that described comparison amplifier connects the CMOS battery is a positive input, an end that connects first, second divider resistance is a reverse input end, and a switch and a resistance also are connected in series between the positive pole of described CMOS battery and the positive input of described comparison amplifier.
4. [claim 4] CMOS battery voltage test device as claimed in claim 1, it is characterized in that: described CMOS battery voltage test device also comprises a connector, the output terminal of described comparison amplifier is connected to described connector, and described connector is used to connect the Basic Input or Output System (BIOS) of a computer.
5. [claim 5] CMOS battery voltage test device as claimed in claim 1 is characterized in that: the value of described comparative voltage at 2V between the 3V.
6. [claim 6] a kind of CMOS battery voltage test device, comprise a voltage generation circuit, some comparison amplifiers, some light emitting diodes and some first divider resistances, described voltage generation circuit connects a power supply, described first resistance is connected in series between described voltage generation circuit and the ground, one input end of each comparison amplifier is connected in the positive pole of a CMOS battery, another input end is connected to the connected node between described first divider resistance, output terminal connects the anode of the light emitting diode of a correspondence respectively, the plus earth of each light emitting diode, the minus earth of described CMOS battery, described voltage generation circuit produces the voltage greater than CMOS battery total voltage, dividing potential drop through described first divider resistance, another input end at each comparison amplifier produces a comparative voltage respectively, each comparison amplifier is by comparing the voltage of its two input end, at its output terminal output high level or low level signal, order about corresponding light emitting diode conducting or end, be greater than or less than corresponding comparative voltage to indicate the current voltage of CMOS battery respectively.
7. [claim 7] CMOS battery voltage test device as claimed in claim 6, it is characterized in that: described voltage generation circuit comprises an adjustable shunting reference source, the negative electrode of described adjustable shunting reference source connects described power supply by a current-limiting resistance, plus earth, the reference edge of described adjustable shunting reference source connects an end of one second, 1 the 3rd divider resistance, the other end of described second divider resistance connects the negative electrode of described adjustable shunting reference source, and the other end of the 3rd divider resistance connects the anode of adjustable shunting reference source.
8. [claim 8] CMOS battery voltage test device as claimed in claim 6, it is characterized in that: the end that described comparison amplifier connects the CMOS battery is a positive input, an end that connects the connected node between described first divider resistance is a reverse input end, and a switch and a resistance also are connected in series between the positive input of described comparison amplifier and the described CMOS battery.
9. [claim 9] CMOS battery voltage test device as claimed in claim 6, it is characterized in that: described CMOS battery voltage test device also comprises a connector, the output terminal of each comparison amplifier is connected to described connector, and described connector is used to connect the Basic Input or Output System (BIOS) of a computer.

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