Abstract: A controlled current limiter having a diode in series with the voltage divider of the current limiting transistor to prevent power dissipation during idle conditions. A switch responsive to the output current is in series with the diode. A clamp responsive to preselected voltage differences clamps the limited current to a fixed valve.
Abstract: An electrostatic charging potential generator for a coating dispenser is useful with, for example, hand-held dispensers where the dispenser can be brought into closely spaced orientation with articles to be coated, or "targets." The generator of the disclosure incorporates a "fold-back" voltage-current characteristic including a reduced voltage-reduced current curve region in which the energy available at the dispenser is less than that necessary for spark ignition of solvents, atomized coating material particles, and the like suspended in the atmosphere around the dispenser.
Type:
Grant
Filed:
April 19, 1982
Date of Patent:
November 27, 1984
Assignee:
Ransburg Corporation
Inventors:
Frederick W. Woodruff, Daniel C. Hughey
Abstract: A current regulator for supplying dc power to a telephone line employs a resistor feed circuit in conjunction with a solid state feed circuit. The dc line current flowing through both such elements is monitored by a sensing circuit which drives the solid state element in a manner to maintain a desired magnitude of dc line current. The resistor value may be arbitrarily chosen so that the circuit power is shared in a desired proportion between the resistor and solid state element. When used in a telephone line in series with ac voice signals the regulator employs a capacitator and diode bridge arrangement to reduce the ac impedance thereof, improve longitudinal balance and allow bi-directional current.
Abstract: An inrush current limiter includes at least a two-terminal circuit in series with a power load having a high gain high current Darlington transistor, a driver transistor for the high gain high current Darlington transistor, a current sensing resistor, a base-drive resistor, and a diode bridge interfaced for providing a peak-current-limiting function by proportional adjustment of the voltage to the power load as a function of current.
Abstract: A full-charge indicator for battery chargers, includes a transistor which is in a conductive state as long as charging current to the battery is not less than a level which indicates that the battery did not reach full charge. When the battery reaches full charge, a voltage drop in a resistor in the charging current path is not sufficient to maintain the transistor in a conducting state, and therefore it is switched off. When this occurs an LED is turned on, to indicate a full charge state of the battery. A photocoupler together with a photocoupler transistor are included. When the transistor is off, the photocoupler activates the photocoupler transistor to shunt out a resistor, thereby reducing the charging current to the battery to a float charging current and prevent the battery from being overcharged and damaged.
Abstract: A battery charger circuit having a temperature-dependent constant voltage region, a constant current region, and a power dissipation limiting current "foldback" region.
Abstract: A current limiting circuit for a switching regulator comprising a current sensing means operably connected to the positive terminal of a source of unregulated power and switching means operably connecting the positive terminal of said power source to the shut down input signal position of the switching regulator. When said current sensing means detects current in the positive terminal exceeding a predetermined value, the circuit of the present invention causes the switching regulator to adjust downward its duty cycle thereby preventing damage to the switching regulator due to current overload.