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Battery Quick Charge System in Notebook PC

IP.com Disclosure Number: IPCOM000108959D
Original Publication Date: 1992-Jul-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Mito, T: AUTHOR [+3]

Abstract

Disclosed is a system for a Ni-Cd battery 1-hour quick charger in a notebook-type PC which is achieved by using only an AC adapter without quick charger. This AC adapter has the constant current and constant voltage characteristics on the one power output terminal. When the system operates in normal operation mode this AC adapter supplies the constant voltage power source to the DC/DC converter, but as the suspend operation mode and power-off state the system controls the switch in the system to connect AC adapter output to the battery and supplies the constant current power source mainly to the Ni-Cd battery. Thus, this constant current works as the 1-hour quick charge current to the Ni-Cd battery.

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This is the abbreviated version, containing approximately 52% of the total text.

Battery Quick Charge System in Notebook PC

       Disclosed is a system for a Ni-Cd battery 1-hour quick
charger in a notebook-type PC which is achieved by using only an AC
adapter without quick charger.  This AC adapter has the constant
current and constant voltage characteristics on the one power output
terminal.  When the system operates in normal operation mode this AC
adapter supplies the constant voltage power source to the DC/DC
converter, but as the suspend operation mode and power-off state the
system controls the switch in the system to connect AC adapter output
to the battery and supplies the constant current power source mainly
to the Ni-Cd battery.  Thus, this constant current works as the
1-hour quick charge current to the Ni-Cd battery.

      Fig. 1 shows the AC adapter output voltage-current curve.  When
the output current is less than 1.0 A, this supplies the 20 VDC
constant voltage power source (domain 1), but if the output connects
to Ni-Cd battery this output is pulled down to the battery, voltage
and supplies the 1.25A constant current power source (domain 2).
This 1.25A constant current power source charges the Ni-Cd battery
which has capacity as 1200 mAH in around 1 hour.  And 8.5 to 18 VDC
voltage range covers the 9 series Ni-Cd battery terminal voltage.

      The system will be best understood with reference to Fig. 2
which describes this quick charger system in block diagram.  When the
system is operating in normal operation mode, system logic controls
P-channel power MOSFET...