Abstract: A current pulse producing, current regulating circuit includes a SCR arranged to pass a current pulse once each positive going half wave input supplied thereto. The SCR is controlled by a control circuit free of current feedback and timing circuitry and responsive to the an unfiltered, rectified A.C. input. The control circuit produces a firing signal, which is applied to the control electrode of the SCR, at a point during the downward swing of each positive going half wave input. The control circuit includes a OR function circuit responsive to the unfiltered rectified input applied to the control circuit and to an output from a circuit also responsive to the unfiltered rectified input; the last mentioned circuit having a hysteresis characteristic. The SCR may be operatively associated with a second SCR and arranged to fire it thereby producing higher amplitude current pulses. Battery charging and forming circuits, as well as off-line power supplies, incorporating the current regulating circuit are disclosed.

Abstract: A battery charger which includes terminals for connection to an electric power source, an electrical charging circuit and an operative arrangement for connecting at least one rechargeable battery cell in series with the charging circuit across the terminals. The battery charger has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A power supply which includes terminals for connection to an electric power source, a storage capacitance, an electrical charging circuit and an operative arrangement for connecting storage capacitance in series with the charging circuit across the terminals. The power supply has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A power supply which includes terminals for connection to an electric power source, a storage capacitance, an electrical charging circuit and an operative arrangement for connecting the storage capacitance in series with the charging circuit across the terminals. The power supply has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A control stage includes a first transistor, which has a collector-emitter path and a base-emitter path. The transistor is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A battery charger which includes terminals for connection to an electric power source, an electrical charging circuit and an operative arrangement for connecting at least one rechargeable battery cell in series with the charging circuit across the terminals. The battery charger has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: Disclosed is a battery operated hand tool which has incorporated directly into its housing a novel battery charging circuit. The charger normally operates off a conventional household power outlet and comprises a solid state switching circuit for recharging the battery with a series of electrical impulses. In some special cases, it can be operated in a non-switching state. External inductance is eliminated by charging the battery through the hand tool motor.

Abstract: Disclosed is an improved circuit for recharging batteries. It can be used with alternating current power sources having a wide range of voltage and frequencies and also with low voltage direct current power sources. A transistor switch is connected in a feedback circuit to have, in effect, a variable resistance such that the charging current is high when the source potential is low and decreases to zero as the source potential increases. Charging efficiency is thereby significantly increased.