Abstract: A dual USB port charging system that can charge at 2.1 A and also at 1 A at the same time when the power supply is only capable of 10 W. A USB port is set as a 2.1 A port via resistor network. If nothing is connected to the other USB port, it charges at 2.1 A. If a device is connected to the other USB port, it automatically detects this condition and momentarily interrupts the 5V output while resetting the USB port to 1 A (the resistor network is changed to 1 A spec). Both devices will then charge at 1 A. If the second device is disconnected while the first device is still charging at 1 A, the charging system will interrupt the output momentarily and reset the network back to 2.1 A. The first device re-registers and is now able to charge at 2.1 A again. If the second USB device is connected first while the first USB port is unused it will also set both ports as 1 A. As the standard USB port is switched between 1 A and 2.1 A network, the current limit is also automatically switched from 1 A to 2.1 A.

Abstract: The AC adapter with automatic built-in power switch comprises of an AC power supply circuit, an AC control circuit, and a monitoring circuit. The monitoring circuit further comprises of a standby power supply, a microcontroller, a circuit for device detection, and a current monitor circuit. The AC power supply circuit is electrically connected to the alternating current source and converts the alternating current to direct current for charging the rechargeable battery of an electronic device. The AC control circuit acts as a switch to turn the AC power supply on and off. The monitor circuit detects whether an electronic device is connected to the adapter and also whether the charging process is completed.

Abstract: The USB AC adapter with automatic built in power switch comprises of an AC power supply circuit, an AC control circuit, a monitoring circuit, and a circuit for the light emitting diode indicator. The monitoring circuit further comprises of a standby power supply circuit, a microcontroller circuit, a circuit for USB chassis detector, a USB data monitor circuit, and a current monitor circuit. The AC power supply circuit is electrically connected to the alternating current source and converts the alternating current to direct current for charging the rechargeable battery of an electronic device. The AC control circuit acts as a switch to turn the AC power supply on and off. The monitor circuit detects whether an electronic device is connected to the adapter and also whether the charging process is completed. The light emitting diode indicator is used to indicate the power and charging status of the adapter.

Abstract: An illuminated universal serial bus (USB) port that is illuminated with a light emitting diode (LED). The illuminated USB port comprises a USB port with a LED disposed directly behind the USB port to illuminate the USB port through the opaque white plastic and the existing openings in the USB port. The illuminated USB port is easily located in low light or dark environments. The illuminated USB port can also indicate the power on status of a USB port.

Abstract: A USB charger comprises a power input, a microprocessor, a resistor network, and a USB port for charging electronic devices through the USB port. The USB charger defaults to provide 2000 mA when power is applied through the power input. When a device is detected at the USB port, it measures device current drain to determine if it is charging. If the device is charging, then it remains in the 2000 mA charging mode. If no current drain is detected, the power supply switches to 1000 mA. If the electronic device recognizes the proper charging network it will begin charging. When the microprocessor detects current drain, it leaves the charging network as is. If still no current drain is detected, the USB microprocessor will attempt the 500 mA charging current. If there is a current drain, it will leave the charging network as is. If no current drain is detected, then it indicates a fault and a LED flashes to indicate the fault.

Abstract: A microprocessor-controlled interface for a cellular radio telephone system enables the user to communicate with such system by means of conventional telephony devices. A standard telephone outlet communicates with the transceiver logic bus through a microprocessor. Switches are provided for controlling the audio path between the handset and the transceiver of the mobile, vehicular-mounted unit in response to the status of the interface outlet. The microprocessor interprets both the transceiver bus and various signals generated by the operation of a device that is plugged into the interface so that the operation of the device is rendered fully compatible with the cellular system. The microprocessor is programmed to decode known manufacturer protocols whereby the interface is able to render itself compatible with various equipment types.

Abstract: A method and apparatus for converting direct coupled data devices to acoustic coupled devices is disclosed. The apparatus consists of an acoustic coupler and associated electronics to provide acoustic coupling to a telephone handset and to connect to a direct connect modem or other data device to allow operation of the direct connect modem in most modes as if directly connected to a telephone line. The device disclosed includes circuitry for off-hook detection for automatically turning on the electronics, so that battery power is only active when required. Other features and characteristics of the device are disclosed.

Abstract: A telephone line interface for direct connect telephone line connections characterized by low cost and minimal package size requirements. The telephone line interface utilizes a small signal transformer with a primary winding couplable to the line by actuation of a relay. A secondary winding of the transformer is coupled to an integrated circuit which performs the functions of ring detect and dial tone detect, and separation of the received signal and the transmit signal when transmitting and receiving simultaneously. Ring signal detection on the secondary side of the coupling transformer substantially reduces the size and cost of the ring detect circuitry, as the secondary of the transformer may be provided with over-voltage protection, whereas the line side of the transformer must survive particularly high surge voltages, thereby requiring high voltage isolation not obtainable by way of conventional integrated circuits. Other aspects and features of the invention are disclosed.

Abstract: Integrated circuit universal frequency shift keyed modems using switched capacitor recursive filters are disclosed. The modems are comprised of two integrated circuits, the first providing the transmitting capability for any of a plurality of conventional transmit modes and the second providing a receive capability for the corresponding modes, including all filtering on chip as is required prior to detection. In this manner, any of a number of conventional modems may be realized using the two chip set and a minimum of external circuitry. Because of the versatility of the chip set, other functions and objectives may be achieved by the use thereof.

Abstract: An interfacing circuit for directly coupling the handset of a telephone to a modem with provision for monitoring the data on the phone line is disclosed. The circuit may be readily connected to standard telephones. Four modes of operation are selectable by a pair of switches. The four modes of operation which may be utilized are as follows: normal phone operation, normal modem operation without the monitoring, normal modem operation with monitoring, and monitoring of data received only. In addition to allowing easy monitoring of data on the phone lines, the invention eliminates the need for a special phone to allow direct connection of a modem to a dial-up phone.