US 6,100,663 A · Inductively powered battery charger

Abstract

Loosely coupled inductive power for charging batteries is rectified from a first power pickup winding and the resulting current source is connected to a battery unit. Each current source is controlled by shorting a second resonant winding. Battery banks may be charged using multiple isolated position-tolerant pickups independently controlled according to the condition of the connected battery unit and by overall commands communicated over an isolated link. The battery unit may be a single cell. In a self-stabilizing bank or monoblock a primary inductive conductor is energized using all the cells, individual cells are separately monitored by control means and any below-average cell can be individually charged from the inductive conductor, thus correcting between-cell variations. The charge in all cells within a bank can be held within 30% to 70% of full charge and prevented from drifting towards full or empty during repetitive charge and discharge times.

Claims11

Dependent claims

A battery charger for a rechargeable battery having one or more cells, the charger inductively transferring power from at least one inductive conductor energized at a high frequency, the charger comprising:

a resonant inductive pickup unit providing to the battery a charging current that is inductively transferred from the at least one inductive conductor to whom said pickup unit is coupled, said pickup unit comprising a first control inductor and a second power-handling inductor, a resonating capacitor, and a rectifier;
said first and second inductors being inductively coupled with each other so that when said first inductor is short circuited said second inductor is substantially decoupled from the at least one inductive conductor;
said pickup unit further comprising a shorting switch varying the coupling between the at least one inductive conductor and said pickup unit by shorting said first inductor to control an amount of energy circulating in said pickup unit and an amount of current passed to the battery.

Dependencies are inferred from the claim text.

Inductively powered battery charger

Life of this patent

Inductively powered battery charger

Life of this patent

Abstract

Claims11