Charger with wide range output voltage

A charger with a wide range output voltage includes a voltage output side, a first constant voltage output unit, a voltage modulation unit and a load voltage detection unit. The first constant voltage output unit generates a first constant voltage. The load voltage detection unit detects a load voltage and transmits the load voltage to the voltage modulation unit. According to the load voltage and a load charging voltage requirement, the voltage modulation unit generates a modulation voltage and transmits the modulation voltage to the first constant voltage output unit. The first constant voltage output unit transmits the first constant voltage and the modulation voltage to the voltage output side. Moreover, the modulation voltage is an n times of a second constant voltage. The n is a positive number.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a charger, and especially relates to a charger with a wide range output voltage.

Description of the Related Art

FIG. 7shows a circuit diagram of a part of an embodiment of the related art charger. The related art charger is used to charge a load20. The load20is, for example but not limited to, a battery module. The charger mentioned above receives an alternating current voltage and converts the alternating current voltage into an output direct current voltage202, and then sends the output direct current voltage202to the load20through a voltage output side102to charge the load20.

Moreover, first a bridge rectifier rectifies the alternating current voltage to obtain a rectified voltage. If an output power of the charger mentioned above is greater than, for example,75watts, a power factor correction circuit processes the rectified voltage. Finally, a main isolating transformer outputs the output direct current voltage202to the load20to charge the load20.

Moreover, a range of the output direct current voltage202is between the lowest voltage of the battery and the designed constant voltage. For example, if the voltage specification of the battery is 9 volts, the range of the output direct current voltage202is between 6 volts and 9 volts. The disadvantage of the charger mentioned above is that the range of the output direct current voltage202is too narrow (namely too small), so that the application range of the charger which has been manufactured is narrow (namely small). For example, the charger mentioned above cannot charge the battery with the low voltage specification or the battery with the high voltage specification.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems, an object of the present invention is to provide a charger with a wide range output voltage.

In order to achieve the object of the present invention mentioned above, the charger includes a voltage output side, a first constant voltage output unit, a voltage modulation unit and a load voltage detection unit. The first constant voltage output unit is electrically connected to the voltage output side. The first constant voltage output unit generates a first constant voltage. The voltage modulation unit is electrically connected to the first constant voltage output unit. The load voltage detection unit is electrically connected to the voltage output side, the first constant voltage output unit and the voltage modulation unit. The load voltage detection unit detects a load voltage and transmits the load voltage to the voltage modulation unit. Moreover, according to the load voltage and a load charging voltage requirement, the voltage modulation unit generates a modulation voltage and transmits the modulation voltage to the first constant voltage output unit. The first constant voltage output unit transmits the first constant voltage and the modulation voltage to the voltage output side. Moreover, the modulation voltage is an n times of a second constant voltage. The n is a positive number.

Moreover, the charger mentioned above further comprises a second constant voltage output unit electrically connected to the voltage modulation unit to supply the second constant voltage to the voltage modulation unit.

Moreover, in the charger mentioned above, the second constant voltage output unit is an alternating-current-to-direct-current power conversion circuit receiving an external alternating current power, or the second constant voltage output unit is an external direct current power.

Moreover, in the charger mentioned above, the second constant voltage output unit is a power conversion circuit receiving an internal alternating current power.

Moreover, in the charger mentioned above, the voltage modulation unit is a buck-boost circuit.

Moreover, in the charger mentioned above, the load voltage detection unit comprises a control unit. According to the load charging voltage requirement, the control unit controls the voltage modulation unit to generate the modulation voltage.

Moreover, the charger mentioned above further comprises a control unit electrically connected to the voltage modulation unit and the load voltage detection unit. Moreover, the load informs the control unit of the load charging voltage requirement through the load voltage detection unit. According to the load charging voltage requirement, the control unit controls the voltage modulation unit to generate the modulation voltage.

Moreover, in the charger mentioned above, a range of the n is between 0.1 and 10.

The advantage of the present invention is that the output voltage of the charger is a wide range voltage, so that the application range of the charger becomes wide (namely big).

DETAILED DESCRIPTION OF THE INVENTION

Please refer to following detailed description and figures for the technical content of the present invention. The figures and detailed description are just for references but the present invention is not limited to it.

FIG. 1shows a block diagram of the first embodiment of the charger with the wide range output voltage of the present invention. A charger10with a wide range output voltage is used to charge a load20. The charger10includes a voltage output side102, a first constant voltage output unit104, a voltage modulation unit106, a second constant voltage output unit105and a load voltage detection unit108. The load voltage detection unit108comprises a control unit110. The voltage modulation unit106is electrically connected to the first constant voltage output unit104, the second constant voltage output unit105, the load voltage detection unit108and the control unit110. The voltage output side102is electrically connected to the first constant voltage output unit104, the load voltage detection unit108, the control unit110and the load20. The load20is further electrically connected to the load voltage detection unit108and the control unit110. InFIG. 1, the dash line between the load20and the load voltage detection unit108is the signal line.

Following content describes the main technical features ofFIG. 1of the present invention:

First, the load voltage detection unit108detects a load voltage of the load20and transmits the load voltage of the load20to the voltage modulation unit106(namely, the load voltage detection unit108informs the voltage modulation unit106of the load voltage of the load20), and the load20informs the control unit110of a load charging voltage requirement of the load20through the load voltage detection unit108. So far, the voltage modulation unit106is aware of the load voltage of the load20, and the control unit110is aware of the load charging voltage requirement of the load20.

The second constant voltage output unit105supplies a second constant voltage10502to the voltage modulation unit106. According to the load voltage of the load20and the load charging voltage requirement of the load20, the control unit110controls the voltage modulation unit106to utilize the second constant voltage10502to generate a modulation voltage10602and the modulation voltage10602is transmitted to the first constant voltage output unit104. The first constant voltage output unit104is used to generate a first constant voltage10402. Finally, the first constant voltage output unit104serially adds (namely, superposition; utilizing the superposition theorem) the modulation voltage10602to the first constant voltage10402to send (the first constant voltage10402and the modulation voltage10602) to the voltage output side102to charge the load20(namely, the load20receives the first constant voltage10402and the modulation voltage10602through the voltage output side102, so that the load20is charged by the charger10).

Moreover, the modulation voltage10602is an n times of the second constant voltage10502. The n is a positive number. For example but not limited to, a range of the n is between 0.1 and 10. The second constant voltage output unit105is, for example but not limited to, an alternating-current-to-direct-current power conversion circuit receiving an external alternating current power, or the second constant voltage output unit105is an external direct current power, or the second constant voltage output unit105is a power conversion circuit receiving an internal alternating current power. The voltage modulation unit106is, for example but not limited to, a buck-boost circuit. The load20is, for example but not limited to, a battery module.

FIG. 2shows a block diagram of the second embodiment of the charger with the wide range output voltage of the present invention. A charger10with a wide range output voltage is used to charge a load20. The charger10includes a voltage output side102, a first constant voltage output unit104, a voltage modulation unit106, a second constant voltage output unit105, a load voltage detection unit108and a control unit110. The voltage modulation unit106is electrically connected to the first constant voltage output unit104, the second constant voltage output unit105and the control unit110. The voltage output side102is electrically connected to the first constant voltage output unit104, the load voltage detection unit108and the load20. The load voltage detection unit108is further electrically connected to the load20and the control unit110. InFIG. 2, the dash line between the load20and the load voltage detection unit108is the signal line.

The main technical features ofFIG. 2of the present invention are similar to the main technical features ofFIG. 1, so it would be omitted here for brevity. The difference is that the load voltage detection unit108detects a load voltage of the load20and transmits the load voltage of the load20to the voltage modulation unit106through the control unit110(namely, the load voltage detection unit108informs the voltage modulation unit106of the load voltage of the load20through the control unit110), and the load20informs the control unit110of a load charging voltage requirement of the load20through the load voltage detection unit108.

FIG. 3shows a circuit diagram of a roughly part of an embodiment of the charger with the wide range output voltage of the present invention. The present invention is not limited byFIG. 3. As shown inFIG. 3, the first constant voltage output unit104is a secondary side first winding of a transformer. The second constant voltage output unit105is a secondary side second winding of the transformer. In an embodiment, the first constant voltage10402is 4.5 volts. The second constant voltage10502is 4.5 volts. The modulation voltage10602is 0.45 volts˜9 volts (namely, in this embodiment, the modulation voltage10602is 0.1˜2 times of the second constant voltage10502). The voltage of the voltage output side102(namely the first constant voltage10402adding to the modulation voltage10602) is 4.95 volts˜13.5 volts, which is wider than the output voltage range (6 volts˜9 volts) of the related art charger mentioned above.

FIG. 4shows a circuit block diagram of a part of an embodiment of the charger with the wide range output voltage of the present invention. Please refer toFIGS. 1˜3again. Moreover, the charger10is connected to an alternating current power supply apparatus30to receive an alternating current power32. The charger10at least further comprises a rectifying circuit120, a power factor correction circuit112, a main circuit114, a switch module122, a first point P1, a second point P2and a third point P3. The main circuit114at least comprises a feedback compensation circuit116, a main isolating transformer118, a fourth point P4, a fifth point P5, a sixth point P6and a seventh point P7.

The rectifying circuit120is used to rectify the alternating current power32to obtain a direct current power34. Then, the power factor correction circuit112compensates a voltage phase and a current phase of the direct current power34. In a primary side of the main isolating transformer118, the main isolating transformer118outputs an auxiliary power36through the fourth point P4to supply working voltages to integrated circuits of the main circuit114. In a secondary side of the main isolating transformer118, the first constant voltage output unit104outputs the first constant voltage10402. The second constant voltage output unit105outputs the second constant voltage10502to the seventh point P7(continuing toFIG. 5to describe in details later). When the switch module122is turned on (the timing of being turned on would be described in details later), the charger10utilizes the first constant voltage10402adding the modulation voltage10602to charge the load20. The main circuit114shown inFIG. 4is the Flyback structure, but when an output power of the charger10is greater than 75 W, the main circuit114often uses the LLC resonance structure, the full bridge structure or the Forward structure to replace the Flyback structure.

FIG. 5shows a block diagram of an embodiment of the voltage modulation unit of the present invention. Please refer toFIGS. 1˜4again. The voltage modulation unit106comprises a buck circuit124, a boost circuit126, an eighth point P8and a ninth point P9. Continuing from the description ofFIG. 4, the buck circuit124receives the second constant voltage10502through the seventh point P7, and cooperates with the boost circuit126to perform a boost-buck process for the second constant voltage10502to obtain the modulation voltage10602. Namely, the buck circuit124and the boost circuit126are configured to buck or boost the second constant voltage10502to obtain the modulation voltage10602. Then, the voltage modulation unit106outputs the modulation voltage10602through the sixth point P6(as shown inFIG. 4).

FIG. 6shows a circuit diagram of an embodiment of the control unit and its peripheral circuits of the present invention. Please refer toFIGS. 1˜5again. The control unit110at least comprises a current detecting resistor R1, a tenth point P10, an eleventh point P11and a twelfth point P12. When the load20(for example, the battery module) is connected to the charger10, first the control unit110reads a voltage of each of a plurality of battery cells of the battery module, and the battery module provides a voltage signal to the control unit110, so that through the third point P3shown inFIG. 4, the charger10is configured to control to turn on a charging power (namely, the first constant voltage10402and the modulation voltage10602) to be transmitted to the battery module. After the battery module utilizes internal integrated circuits to detect that the battery cells are normal, the battery module sends out a corresponding value to the control unit110, so that the control unit110sends control signals to the buck circuit124and the boost circuit126through the eighth point P8and the ninth point P9shown inFIG. 5respectively to control the buck circuit124and the boost circuit126to adjust the second constant voltage10502to obtain the modulation voltage10602. The control unit110and its peripheral circuits detect a voltage value of the voltage output side102through the twelfth point P12shown inFIG. 6and the voltage value of the voltage output side102is sent to the control unit110. Then the control unit110controls the switch module122shown inFIG. 4to be turned on through the second point P2shown inFIG. 4to charge the load20.

Moreover, the control unit110controls an initial value of a charging current through the tenth point P10shown inFIG. 6, wherein the charging current charges the load20. When the battery module is charged, the following data would be instantaneously sent to the control unit110to determine to control the charging current and to monitor statuses of the battery cells:

1. A voltage value of each of the battery cells.

2. The current detecting resistor R1shown inFIG. 6detects the charging current and feedbacks to the control unit110. A pulse width modulation signal which controls the charging current is adjusted through the eleventh point P11shown inFIG. 6.

The advantage of the present invention is that the output voltage of the charger is a wide range voltage, so that the application range of the charger becomes wide (namely big).