Integrated power supply apparatus for information appliances

An integrated power supply apparatus for information appliances includes a power supply input unit, a rectification unit and a voltage boosting unit. The previous design of transforming low voltage to high voltage through a voltage boosting unit (inverter) is changed to transforming to medium voltage through the rectification unit then is transformed to high voltage through the voltage boosting unit. Therefore loss on the low voltage power supply is eliminated, and performance may increase from 64% to about 80% or more. Thus the low voltage power supply module that otherwise should have extra power and greater watts may be shrunk and power supply efficiency may increase.

FIELD OF THE INVENTION

The present invention relates to an integrated power supply apparatus for information appliances and particularly to a power supply apparatus for reducing power supply loss to information appliances and improving performance.

BACKGROUND OF THE INVENTION

At present many information appliance products such as plasma TV and liquid crystal display, aside from various electronic circuits, have a power supply device to support the information appliances. The power supply device generally provides only low voltage electric power. Refer toFIG. 1for a conventional power supply for the back light panel of a liquid crystal display. The back light panel includes cold cathode fluorescent lamps (CCFLs) that require a high voltage (as high as hundred or even thousand volts) to activate.

Namely, input alternating current (AC) voltage is transformed by a medium voltage rectification unit to become medium voltage direct current (DC) to be output. And the medium voltage DC is further transformed by a conversion unit to become low voltage DC to be output. The low voltage DC is processed by a voltage boosting unit (inverter) to output high voltage AC. The high voltage AC may drive the CCFLs. The efficiency of the voltage boosting unit is 80%. When the conversion unit at the previous stage also has efficiency of 80%, total efficiency (the voltage delivered to the CCFLs) is 80%×80%=64%.

As a large size liquid crystal display could use up to 20 lamp tubes, and each lamp tube has energy loss of 5W-10W, total energy loss could reach 36W to 72W. Thus the power supply device for the information appliances incurs a lot of power loss. Performance also cannot be improved.

SUMMARY OF THE INVENTION

The primary object of the invention is to resolve the aforesaid disadvantages and eliminate the drawbacks of the prior art. The power supply apparatus for information appliances of the invention eliminates the loss occurred to the low voltage power supply, thus can reduce power loss of power supply and improve performance.

To achieve the foregoing object, the integrated power supply apparatus for information appliances of the invention includes a power supply input unit, a rectification unit and a voltage boosting unit. The power supply input unit delivers an AC voltage to the rectification unit which rectifies and outputs medium voltage DC. The medium voltage DC is processed by the voltage boosting unit to obtain high voltage AC. Thus power supply loss occurs only to the voltage boosting unit, and total power loss can be reduced and performance may be improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer toFIG. 2for the circuit block diagram of the integrated power supply apparatus of the present invention. As shown in the figure, the integrated power supply apparatus of the invention includes a power supply input unit1, a rectification unit2, a voltage boosting unit3, a conversion unit4and a load5. The rectification unit2directly outputs medium voltage power supply to the voltage boosting unit3. Hence power loss occurs only to the voltage boosting unit3. As a result, total power loss can be reduced and performance may be improved

In the structure of the invention set forth above, the power supply input unit1provides AC voltage of 110-220V.

The rectification unit2has an input end21to receive input from the AC power supply. The rectification unit2rectifies the AC power supply to become a medium voltage DC in a range about 150 DCV and 300 DCV to be output. The rectified DC voltage is output through a first output end22and a second output end23.

The voltage boosting unit3has a great power (watts) and includes an inverter with total performance at about 80%. The voltage boosting unit3has an input end connecting to the first output end22of the rectification unit2to transform the DC voltage output from the rectification unit to become a high voltage AC for outputting.

The conversion unit4is connected to the second output end23of the rectification unit2to transform the medium voltage DC output from the rectification unit2to a low voltage (such as 5V, +/−12V, +/−24V, etc.) DC41output to supply other circuits that require low voltage DC.

The load5may be, but not limited to CCFLs, ozone generators, or negative ions generators. The load5is connected to the output end of the voltage boosting unit3and driven by the high voltage output from the voltage boosting unit3.

When the power supply input unit1delivers AC power supply input to the rectification unit2, the rectification unit2rectifies the AC power supply to a medium voltage DC power supply (150DCV -300DCV) to be output. The medium voltage DC is output respectively to the voltage boosting unit3and the conversion unit4. The voltage boosting unit3transforms the medium voltage DC output from the rectification unit2to high voltage AC about 500VAC-1000VAC to be output. The voltage may be used to drive the load5connected to the voltage boosting unit3.

As the voltage boosting unit (inverter)3that transforms the original low voltage to high voltage is designed to boost the medium voltage DC that has been rectified by the rectification unit2to high voltage, thus loss that would otherwise occur to the low voltage power supply is eliminated. Performance can increase from 64% to about 80% or more due to loss occurs only to the voltage boosting unit3. The original low voltage power supply module that should have been designed for providing extra power and more watts can be shrunk. Shrinking of the power supply module further improves the performance.

Refer toFIG. 3for another embodiment of the invention. The integrated power supply apparatus for information appliances of the invention employs a rectification unit2which rectifies AC voltage to medium voltage DC for outputting. The rectification unit2may be a half-wave bridge rectification or a full-wave bridge rectification, or adopt a regulated voltage approach to transform AC voltage to a medium voltage DC for outputting.

In the mean time, the half-wave bridge rectification or the full-wave bridge rectification is bridged by a switch unit6which may be a mechanical type or an electronic type. When the rectification unit2is the half-wave bridge rectification or the full-wave bridge rectification, the switch unit6provides the switch function.

Refer toFIG. 4for yet another embodiment of the invention. The integrated power supply apparatus for information appliances of the invention employs a rectification unit2which includes a half-wave or full-wave voltage doubling unit7that consists of at least one capacitor and diode to double the input AC voltage to become a medium voltage DC for outputting.

Refer toFIG. 5for still another embodiment of the invention. The voltage boosting unit3used in the integrated power supply apparatus for information appliances of the invention may be a conventional coil type (non-resonant pulse width modulation—PWM) or coil resonant type, or a piezoelectric ceramic transformer to transform medium voltage DC to high voltage AC for outputting.

Refer toFIGS. 6,7and8for embodiments of the invention in use. The rectification unit2rectifies AC voltage to medium voltage DC for outputting. The medium voltage DC output may be directly connected to a CCFL driving device which may be a conventional coil or a high voltage AC inverter. Then the conventional CCFL driving device can reduce power loss and performance may increase.

Moreover, the conversion unit4used in the invention may be multiple sets, a single set, or a positive and negative power supply type.

While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are tended to cover all embodiments which do not depart from the spirit and scope of the invention.