France/scott Fetzer Company

Cooper Technologies Company

France/a Scott Fetzer Company

Other

William Thomas Hopkins

Anthony William Banks

Alan M Smith

Scott Edward Rhodes

Robert L Towe

Charles A Schlemm

Louis B Pickvet

David Henrik Riesland

Thomas Eugene Dean

Hugh Edward Hickerson, Jr

Improving start-up time of a light emitting diode (led) driver at lower input voltage is accomplished with a quick start circuit comprising a constant current source that replaces the traditional trickle charge start-up path for charging of a Vcc capacitor supplying operating voltage to an SMPS controller. Also the constant current source will only be operational during SMPS start-up, then will turn off after the SMPS is capable of producing its own regulated power supply to the Vcc terminal of the SMPS controller, thereby minimizing E/R power losses in the SMPS.

Method and system for improving start-up time of a light emitting diode (LED) driver at reduced input voltage

Total harmonic distortion (THD) at the AC line input of a power factor corrected (PFC) flyback switch mode power supply (SMPS) is reduced by adding additional current injection to the current programming signal of a PFC controller during the period of the line cycle where the AC input current wave shape is most flattened, i.e., around the peak portion of the AC line voltage. The input current drawn by the PFC flyback SMPS will then more closely resemble a desired sinusoidal waveform. A voltage dependent non-linear resistance is coupled in parallel with the normal current injection resistor that supplies current to the PFC flyback controller multiplier input to inject appropriate values of additional current into the PFC flyback controller based upon the AC input voltage value(s) so as to better shape the AC input current to the desired sinusoidal waveform.

Reducing total harmonic distortion in a power factor corrected flyback switch mode power supply

A circuit for dimming a lamp is provided. The circuit includes a triac dimmer that adjusts the voltage level of an input AC waveform based on the setting of a dimmer switch. The output of the dimmer is provided to a power supply circuit that drives the lamp based on the voltage level at the dimmer output. The power supply circuit includes a compensation circuit that compensates for loss of dimmer output signal caused by the triac when the dimmer switch is adjusted for full output. The compensation circuit is configured to engage at dimmer output voltage levels between full power supply voltage and a voltage threshold. The voltage threshold may be based on the dimmer output voltage level when the dimmer switch is set for full output. The compensation circuit essentially disengages to allow the lamp to dim when the dimmer output voltage level falls below the threshold.

Lamp driver with triac dimmer compensation

A gas discharge lamp power supply having a base, a pair of opposed side walls extending from the base, and opposed first and second end walls extending from the base between the opposed side walls. The first end wall has a sloped wall extending angularly between the side walls, and two input terminals are mounted on the sloped wall. In another embodiment, the power supply has a control with a nonvolatile memory for storing an error code in response to a detected fault condition, thereby permitting the error code to be displayed upon power being removed from and then, subsequently reapplied.

Gas discharge lamp power supply

A battery charger for a lead acid battery having a power supply with an input connected to an AC signal and an output connected to the battery. The power supply provides a charge current to the battery. A clock connected to the AC signal provides clock pulses having transitions synchronized with zero crossings of the AC signal. A voltage monitor connected to the battery detects a battery voltage substantially simultaneously with a zero value of the charge current. A charge mode control is connected to the clock and the voltage monitor for commanding different battery charge currents. The voltage monitor includes a temperature compensation circuit. The battery charger includes a display module that can be placed at a location remote from the battery charger and convenient to the user. The battery charger executes a battery charge cycle in which absorption and equalization charge times are variable and automatically set as a function of the state of discharge of the battery, that is, as a function of the bulk charge time. During an initial evaluation period, the battery is tested for a deep discharge condition, and if detected, a desulfation charge current is automatically applied for a time period, for example, two hours.

Method and apparatus for charging a lead acid battery

A power supply circuit detects ground fault paths, and miswiring of the load, using a test mode in which electrical power is applied to only one power output terminal of the power supply relative to the ground terminal, while substantially no electrical power is applied to the second power output terminal relative to the ground terminal. If application of power during the test mode causes substantial current flow through ground, then there is a ground fault path, or an incorrect connection between the midpoint of the load and ground. The power supply further includes unique features for signaling the presence and kind of fault it has detected; the power supply is capable of distinguishing between ground faults in at least two different locations, and when a fault is detected, the power supply signals the presence of the fault and its location, e.g., by timed blinking of the connected discharge light. These features are enhanced by a diagnostic analyzer for connection to the power supply. The diagnostic analyzer monitors power flow from the output terminals of the diagnostic analyzer to the input terminals of the power supply, and evaluates the power flow to identify power flow patterns indicative of a fault and the kind of fault. The power supply also reduces inrush current by disconnecting and reconnecting power to the transformer primary winding in opposite half-cycles of the alternating current electrical power.

Diagnostic functions for power supply

Neon power supply with midpoint ground detection and diagnostic functions

A power supply power supply circuit of the kind which includes a transformer having primary and secondary windings and an oscillator for driving the primary winding in a bi-directional fashion, suitable for driving gas discharge lighting such as neon signs, which prevents dangerous overvoltage output conditions and detects relatively low level ground fault currents. The transformer includes a clamp winding which is in proximity to and capacitively coupled to the secondary winding. The terminals of the clamp winding are connected to a current imbalance detection circuit for detecting imbalance between the current flowing into one clamp winding terminal and the current out of the other clamp winding terminal. In a ground fault condition, ground fault current flows in an unbalanced fashion into the clamp winding terminal(s), and through the capacitive coupling to the secondary winding. This ground fault current is detected by the current imbalance detection circuit, causing the current imbalance detection circuit to generate an electrical signal indicative of ground fault current, which shuts down the oscillator.

Neon power supply with improved ground fault protection circuit

A transformer control circuit which includes a ground fault detection circuit that detects ground fault currents in the transformer secondary and delivers a ground fault detection signal to the primary circuit. This circuit derives power from the secondary winding and transmits the ground fault detection signal through an optical isolation barrier, thus avoiding the use of an auxiliary transformer. The ground fault detection circuit further includes safety features for detecting whether AC power is being supplied without earth ground being connected, and/or whether there is an undesired electrical connection between a transformer output connection and earth ground, which would defeat the ground fault detection circuit.

Safety-enhanced transformer circuit

A ballast for driving a gas discharge tube light with overvoltage protection and dimming. A clamp winding coupled to the internal DC power source prevents overvoltage of the secondary terminals by permitting induced current flow in the clamp winding if the clamp winding voltage exceeds that of the internal DC power source. The transformer core includes a shunt leg which supports a dimmer control winding. When the dimmer control winding is open-circuited, magnetic flux is shunted away from the secondary winding, reducing the light intensity; when the dimmer control winding is short-circuited, currents induce in the dimmer control winding prevent substantial of magnetic flux density and increase the light intensity.

Growing community of inventors

Dickson, TN, United States of America

William Thomas Hopkins