Battery management system with MOSFET boost system

• US 9,385,706 B2
• Filed: 05/19/2014
• Issued: 07/05/2016
• Est. Priority Date: 04/28/2011
• Status: Active Grant

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Inventors: Deam, David
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): SKIBINSKI, THOMAS S
• Application Number:
  US14/281,653
• Publication Number:
  US 20140333366A1
• Time in Patent Office: 778 Days
• Field of Search: 327/538, 327108-112, 307/24, 307/43, 326/82, 326/83, 323/263
• US Class Current: 1/1
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H03K 17/302 in field-effect transistor switches
• CPC Class Codes: H03K 2217/0027 Measuring means of, e.g. currents through or voltages across the switch
• CPC Class Codes: H03K 2217/0054 Gating switches, e.g. pass gates
• CPC Class Codes: H03K 2217/0081 Power supply means, e.g. to the switch driver

Abstract

A boost converter for driving the gate of n-channel MOSFET power devices is described. The boost converter includes a monitoring circuit and a kick start circuit to quickly bring the boost converter online when required to drive the MOSFET on.

Claims

1. A boost system for a removable battery configured to provide high current, the removable battery also having low internal impedance, for powering a device, comprising:

a first rechargeable cell having a positive and a negative terminal;

a second rechargeable cell having a positive and a negative terminal connected in series with the first rechargeable cell;

a battery connector for connecting the battery to a charger or a device to be powered by the battery;

a main bus connecting the positive terminal of the first rechargeable cell with a positive connector of the battery connector and also connecting the negative terminal of the second rechargeable cell to a negative connector of the battery pack connector;

an n-channel MOSFET configured as a low impedance high current switch disposed between the positive connector of the battery connector and the positive terminal of the first rechargeable cell;

a boost converter configured to supply a boost voltage to a gate of the n-channel MOSFET;

a boost converter power supply for providing a first current to the boost converter to power the boost converter;

a second boost converter power supply for providing a second current to the boost converter, the second current being larger than the first current, the second boost converter power supply including a timer for providing current flow from the second boost converter power supply for a selected period of time, the second boost converter power supply includes a pull down resistor connected to an output of the first boost converter power supply.

2. The boost system of claim 1, further comprising a voltage monitoring circuit for monitoring the output of the boost converter.

3. The boost system of claim 2, further comprising a switch disposed between the boost converter and the gate of the n-channel MOSFET, the switch responsive to a signal from the voltage monitoring circuit to provide a voltage to the gate of the n-channel MOSFET when the voltage monitoring circuit determines the output of the boost converter exceeds a selected threshold and is stable.

4. The boost system of claim 2, wherein the voltage monitoring circuit includes a hysteresis monitor.

5. The boost system of claim 1, wherein the first current is about 2 milliamps.

6. The boost system of claim 1, wherein the second current is about 30 milliamps.

7. The boost system of claim 1, further comprising a boost enable switch, the boost enable switch being responsive to a signal from a processor to turn on the first and second boost converter power supplies.

8. A compact, high power battery utilizing the boost system of claim 1.