Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. Preferably, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. Preferably, each module shares a substantially equal portion of the output load.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. Preferably, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. Preferably, each module shares a substantially equal portion of the output load.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

Abstract: A transient recovery circuit in a switching regulator responds to relatively quick changes in load currents to suppress output voltage overshoots or undershoots. The transient recovery circuit operates independently of a regular feedback circuit. The transient recovery circuit can be used in a single phase or a multiphase switching regulator. In one embodiment, the transient recovery circuit overrides a control voltage from the regular feedback circuit to control the duty cycle of a pulse-width modulation circuit in the switching regulator during transient conditions. In another embodiment, the transient recovery circuit controls a dedicated transient phase in a multiphase switching regulator. The transient recovery circuit is inactive during non-transient conditions.

Abstract: A transient recovery circuit in a switching regulator responds to relatively quick changes in load currents to suppress output voltage overshoots or undershoots. The transient recovery circuit operates independently of a regular feedback circuit. The transient recovery circuit can be used in a single phase or a multiphase switching regulator. In one embodiment, the transient recovery circuit overrides a control voltage from the regular feedback circuit to control the duty cycle of a pulse-width modulation circuit in the switching regulator during transient conditions. In another embodiment, the transient recovery circuit controls a dedicated transient phase in a multiphase switching regulator. The transient recovery circuit is inactive during non-transient conditions.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. Preferably, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. Preferably, each module shares a substantially equal portion of the output load.

Abstract: A plurality of single-phase synchronizing converter automatically synchronize on a peer-to-peer basis. Each synchronizing converter is configured as a DC-to-DC converter. The synchronizing converters operate in parallel as a multi-phase converter. A common bus between the synchronizing converters includes a sync line and a common phase control line. Proper phasing automatically occurs when power is applied, and the phasing changes automatically as converters are added or removed. When the system powers up, the converters arbitrate for phase position. The phasing positions are random, but the phasing is relatively symmetrical regardless of the number of phases. In one embodiment, a hot-swappable converter module can be plugged into any location of a parallel multiphase bus to produce a common output voltage. When an additional module is plugged in, the converters readjust their phases to maintain phase symmetry. In one embodiment, each module shares a substantially equal portion of the output load.

Abstract: A transient recovery circuit in a switching regulator responds to relatively quick changes in load currents to suppress output voltage overshoots or undershoots. The transient recovery circuit operates independently of a regular feedback circuit. The transient recovery circuit can be used in a single phase or a multiphase switching regulator. In one embodiment, the transient recovery circuit overrides a control voltage from the regular feedback circuit to control the duty cycle of a pulse-width modulation circuit in the switching regulator during transient conditions. In another embodiment, the transient recovery circuit controls a dedicated transient phase in a multiphase switching regulator. The transient recovery circuit is inactive during non-transient conditions.

Abstract: A transient recovery circuit in a switching regulator responds to relatively quick changes in load currents to suppress output voltage overshoots or undershoots. The transient recovery circuit operates independently of a regular feedback circuit. The transient recovery circuit can be used in a single phase or a multiphase switching regulator. In one embodiment, the transient recovery circuit overrides a control voltage from the regular feedback circuit to control the duty cycle of a pulse-width modulation circuit in the switching regulator during transient conditions. In another embodiment, the transient recovery circuit controls a dedicated transient phase in a multiphase switching regulator. The transient recovery circuit is inactive during non-transient conditions.

Abstract: A transient recovery circuit in a switching regulator responds to relatively quick changes in load currents to suppress output voltage overshoots or undershoots. The transient recovery circuit operates independently of a regular feedback circuit and overrides a control voltage from the regular feedback circuit to control the duty cycle of a pulse-width modulation circuit in the switching regulator during transient conditions. The transient recovery circuit is inactive during non-transient conditions. The transient recovery circuit can be used in a single phase or a multiphase switching regulator.

Abstract: An efficient multiphase switching regulator uses sensed voltages to achieve accurate forced current sharing and programmable current sharing. The voltage waveforms at the input of respective inductors are low-pass filtered to produce sensed voltages which are proportional to the duty cycles of the respective voltage waveforms. The sensed voltages are compared. The comparisons are used to adjust PWM circuits which control the duty cycles of the voltage waveforms of the respective inductors. Substantially identical sensed voltages at the inputs of identical inductors result in substantially identical output currents from respective inductors. The ratio of the output currents from respective inductors can be changed by adjusting a variable resistor that changes the fractions of respective sensed voltages being compared.

Abstract: An efficient multiphase switching regulator uses sensed voltages to achieve accurate forced current sharing and programmable current sharing. The voltage waveforms at the input of respective inductors are low-pass filtered to produce sensed voltages which are proportional to the duty cycles of the respective voltage waveforms. The sensed voltages are compared. The comparisons are used to adjust PWM circuits which control the duty cycles of the voltage waveforms of the respective inductors. Substantially identical sensed voltages at the inputs of identical inductors result in substantially identical output currents from respective inductors. The ratio of the output currents from respective inductors can be changed by adjusting a variable resistor that changes the fractions of respective sensed voltages being compared.

Abstract: A single sided dc-dc converter utilizes a switched resonant circuit having pulsed currents and voltages. A pair of MOSFET switches are used to alternately charge a capacitor in series with an inductor from an input voltage source, and then to discharge the capacitor through a second inductor into an output capacitor. The charge and discharge currents are in the form of pulses, and flow in the same direction into the output capacitor to directly establish the output voltage. Both the "on" and "off" switching of each of the MOSFET switches is accomplished at zero current.For a given input voltage source, the output voltage of the converter is determined by the size of the output capacitor and the repetition rate of the "on-off" charge-discharge sequences. The voltage output of the converter is monitored, and a controller responsive to changes in the output voltage varies the repetition rate of the charge-discharge cycle to maintain constant voltage output.

Abstract: A capstanless magnetic tape transport system employs supply and take-up motors, the supply motor being employed as a drag motor. The supply motor is controlled to meter tape at a predetermined speed, and the take-up motor is of such design that, in response to a constant voltage applied thereto, it provides constant tension to the tape being metered.

Abstract: Apparatus for detecting the speed of an electric motor that forms part of a web transport system employs a bridge circuit adapted to measure the back emf of the motor. Thermally induced changes to the armature resistance of the motor are compensated for by varying the bridge resistances, such changes being identified by comparing the bridge circuit signal output with a reference signal.