Abstract: A stringed musical instrument having a counter tensioning system to counteract the string tension. The counter tensioning system creates a force in opposition to the string tension preventing bowing of the neck. The counter tensioning system reduces the need for periodic adjustments and calibration. The counter tension system also allows for precise calibration of the neck bow to accommodate user preferences.

Abstract: A bi-directional boost circuit for power factor correction includes a power factor control circuit and a pair of diodes, a pair of inductors, and a pair of switches. A first diode, a second diode, a first inductor, a second inductor, a first switch, and a second switch convert the AC input voltage, rectify the AC input voltage, and output an intermediate DC voltage. The power factor control circuit receives the AC input voltage and receives the intermediate DC voltage. The power factor control circuit regulates the DC output voltage. Based on the AC input voltage and the intermediate DC output voltage, the power factor control circuit controls an inductor current waveform by driving the first switch and the second switch to create a substantially sinusoidal current as seen by the power source that is in phase with the AC input voltage.

Abstract: Power supply equipment includes a power converter and connector adapters for coupling between the converter and various appliances. The connector adapters bear respective adapter indicators. A particular connector adapter, bearing a corresponding adapter indicator, is chosen for mating with a particular appliance. The power converter generates selectable output voltages which are identified by respective converter indicators. The power converter output voltage is selected so that the converter indicator matches the indicator on the adapter chosen for the particular appliance.

Abstract: A power converter with a fan assembly cools down a temperature of the power converter. The power converter with a fan assembly includes a housing, a plate, and a second plate. The housing includes a fan assembly (which is integral to the housing) to draw in air. The plate is coupled to the housing to create an air channel between the plate and the housing and the second plated is coupled to the housing to create a second air channel between the second plate and the housing. The fan assembly draws in air through one of the air channel or the second air channel and moves air out through the other of the air channel and the second air channel to cool down the temperature of the power adapter.

Abstract: A bidirectional boost circuit for power factor correction includes a power factor control circuit and a pair of diodes, a pair of inductors, and a pair of switches. A first diode, a second diode, a first inductor, a second inductor, a first switch, and a second switch convert the AC input voltage, rectify the AC input voltage, and output an intermediate DC voltage. The power factor control circuit receives the AC input voltage and receives the intermediate DC voltage. The power factor control circuit regulates the DC output voltage. Based on the AC input voltage and the intermediate DC output voltage, the power factor control circuit controls an inductor current waveform by driving the first switch and the second switch to create a substantially sinusoidal current as seen by the power source that is in phase with the AC input voltage.

Abstract: A switching power supply includes a source of DC voltage and a transformer having primary and secondary windings. A switching circuit is coupled between the DC voltage and the primary winding to provide alternating current to the primary winding. A rectifier circuit is coupled to the secondary winding to provide a DC output voltage. A controller circuit controls the switching circuit to modulate the alternating current provided to the primary winding. A circuit receives a first input signal having a magnitude which is determined by the DC output voltage and a second input signal having a magnitude which is determined by a selected position of a multiposition switch. An output of the circuit generates a feedback signal which is coupled to the controller circuit.

Abstract: A power supply system includes an adapter to receive power from a power source, and output a regulated output voltage (Vout). A tip receives Vout from the adapter, and output Vout to an electronic device. The tip includes active circuitry to adjust a programming voltage (Vprog). Vprog is fed back to the adapter to control a magnitude of Vout.

Abstract: A detachable tip, utilized with a power adapter, includes a memory, a receiver, and a transmitter. The memory stores a character string, the character string identifying whether an approved power adapter is coupled to the detachable tip. The receiver receives an identification request from an electronic device. In response to the identification request, a transmitter transmits the stored character string to the electronic device. A controller may extract the character string from the memory and send the character string to the transmitter. Instead of a character string, the memory may store a value, which is representative of a maximum power output available. A detachable tip may include an input connector and an output connector. The input connector receives a value from the power adapter, the value being representative of a maximum power available from the power adapter. The output connector passes through the value to the electronic device.

Abstract: A programmable AC/DC power converter receives a plurality of input voltages and outputs a single voltage from an input voltage system. A transformer receives the single voltage. One of the plurality of input voltages is provided at a center tap of a secondary winding of the transformer. A transformed voltage is output. A rectifier receives the transformed voltage and outputs a DC voltage. A buck regulator receives a DC voltage, creates a regulated voltage, and outputs the regulated voltage and a regulated current to a portable appliance. A error correction system receives a programming signal and regulated signals and verifies that the regulated signal to programming signal ratio is within an acceptable range.

Abstract: A power converter with a fan assembly cools down a temperature of the power converter. The power converter with a fan assembly includes a housing, a plate, and a second plate. The housing includes a fan assembly (which is integral to the housing) to draw in air. The plate is coupled to the housing to create an air channel between the plate and the housing and the second plated is coupled to the housing to create a second air channel between the second plate and the housing. The fan assembly draws in air through one of the air channel or the second air channel and moves air out through the other of the air channel and the second air channel to cool down the temperature of the power adapter.

Abstract: A power supply for providing a regulated DC output power is disclosed. An interface is coupled to the power supply and the interface provides a plurality of operational voltages to any one of a plurality of electronic devices. The plurality of operational voltages correspond to input power requirements of respective portable electronic devices. The interface may include a regulator which provides a second of the plurality of operational voltages at a different value than a first of the plurality of operational voltages.

Abstract: A progammable power supply for providing a regulated DC output power is disclosed. The power supply provides the output power to any one of a plurality of electronic devices adapted for receiving the output power at an operational voltage or an operational current. The power supply receives a programming signal to maintain the output power at the operational voltage or operational current associated with a particular selected electronic device. Accordingly, by varying the programming signal, the power supply can be programmed to provide output power to any one of several electronic devices having differing input power requirements.

Abstract: A progammable power supply for providing a regulated DC output power is disclosed. The power supply provides the output power to any one of a plurality of electronic devices adapted for receiving the output power at an operational voltage or an operational current. The power supply receives a programming signal to maintain the output power at the operational voltage or operational current associated with a particular selected electronic device. Accordingly, by varying the programming signal, the power supply can be programmed to provide output power to any one of several electronic devices having differing input power requirements.

Abstract: A progammable power supply for providing a regulated DC output power is disclosed. The power supply provides the output power to any one of a plurality of electronic devices adapted for receiving the output power at an operational voltage or an operational current. The power supply receives a programming signal to maintain the output power at the operational voltage or operational current associated with a particular selected electronic device. Accordingly, by varying the programming signal, the power supply can be programmed to provide output power to any one of several electronic devices having differing input power requirements.

Abstract: A progammable power supply for providing a regulated DC output power is disclosed. The power supply provides the output power to any one of a plurality of electronic devices adapted for receiving the output power at an operational voltage or an operational current. The power supply receives a programming signal to maintain the output power at the operational voltage or operational current associated with a particular selected electronic device. Accordingly, by varying the programming signal, the power supply can be programmed to provide output power to any one of several electronic devices having differing input power requirements.

Abstract: A cradle casing has a DC/DC adapter to receive DC power from a DC power source and generate a first DC power signal. A sleeve accepts an AC/DC adapter, and guides movement of the AC/DC adapter when the AC/DC adapter is inserted into the cradle casing. The AC/DC adapter is capable of receiving AC power from an AC power source and generating a second DC power signal. A circuit receives at least one of the first DC power signal and the second DC power signal and outputs a third DC power signal.

Abstract: A key coded power connector and a system and method for making key coded power connections are disclosed. A power connector such as a power adapter connector is configured with either a visual keying system, a physical keying system, or both. The physical keying system prevents a user from connecting a host device to a connector of the power source which does not support that host device. The visual keying system provides the user with an early indication that the particular device is not supported by a power source. The user can visually compare a marking key on the host device with the making key on the power connector and determine whether or not the power source is capable of outputting sufficient power to operate the device. The visual and physical keying systems prevents a user from improperly connecting a host device to a power source which does not support that device.

Abstract: A key coded power connector and a system and method for making key coded power connections are disclosed. A power connector such as a power adapter connector is configured with a visual and physical keying system. The physical keying system prevents a user from connecting a host device to a connector of the power source which does not support that host device. The visual keying system provides the user with an early indication that the particular device is not supported by a power source. The user can visually compare a marking key on the host device with the making key on the power connector and determine whether or not the power source is capable of outputting sufficient power to operate the device. The combination of the visual and physical keying systems prevents a user from improperly connecting a host device to a power source which does not support that device.

Abstract: A power converter with a fan assembly cools down a temperature of the power converter. The power converter with a fan assembly includes a housing, a plate, and a second plate. The housing includes a fan assembly (which is integral to the housing) to draw in air. The plate is coupled to the housing to create an air channel between the plate and the housing and the second plated is coupled to the housing to create a second air channel between the second plate and the housing. The fan assembly draws in air through one of the air channel or the second air channel and moves air out through the other of the air channel and the second air channel to cool down the temperature of the power adapter.

Abstract: A power supply system includes a power source and a control circuit. The power source provides DC power. A control circuit, which is remote to the power source, receives the DC power and provides a first DC power signal to an electronic device. The control circuit includes an active component to provide at least one of a voltage control output or a current control output to the power source to regulate the DC power. A power supply system includes a power source and a control circuit. The control circuit is remote to the power source, receives the DC power, and provides the DC power to an electronic device. The control circuit includes a microprocessor to provide at least one of a voltage control output and a current control output to the power source to regulate the DC power.