Power supply system providing power and analog data signal for use by portable electronic device to control battery charging

What is this patent about?

’187 is related to the field of power supply systems for portable electronic devices, specifically addressing the need for intelligent communication between a power adapter and a device like a notebook computer. In environments with limited power capacity, such as airplane cabins using EMPOWER outlets, drawing excessive current to simultaneously run a device and charge its battery can trigger safety cut-offs or create fire hazards. The invention provides a mechanism for the adapter to communicate its power capabilities to the device to prevent these issues.

The underlying idea behind ’187 is the use of a specialized four-conductor interface that enables a bidirectional handshake between the power supply and the electronic device. Rather than relying on simple mechanical switches or passive resistors, the system uses active data circuitry to respond to an interrogation signal from the device. By providing a specific analog signal back to the device, the adapter can dynamically communicate its maximum power capacity or the nature of its input source, allowing the device to adjust its power draw accordingly.

The claims of ’187 focus on a power supply system and connector architecture featuring four distinct conductors: two for DC power and ground, one for receiving an initiation signal from the portable device, and one for transmitting a responsive analog signal. The independent claims specifically protect the mechanism where the portable device determines a parameter level of this analog response—such as a specific voltage or current magnitude—to decide whether to enable or disable the charging of its internal battery.

In practice, the system utilizes a detachable tip or cable end that houses the data circuitry, which may include a microcontroller or a dedicated memory chip. When the device is plugged in, it sends a first signal to 'wake up' or query the adapter. The adapter's data circuitry then generates a response where the physical characteristics of the signal, rather than just a digital code, represent the potential power output level. This allows the device to distinguish between a high-wattage wall outlet and a current-limited vehicle or aircraft source.

This approach differs from prior solutions that used simple three-pin connectors with a floating or grounded data line, which were prone to user error or mechanical failure. By requiring a bidirectional handshake and an active analog response, the invention ensures that the electronic device receives a reliable confirmation of the power source's limits. This prevents the device from inadvertently drawing too much current if a connector is damaged or if an incorrect adapter tip is used in a sensitive environment like an airplane.