Abstract: A high current battery charger of the driven blocking oscillator type includes a three-winding transformer. The primary winding is connected in series with the collector-emitter path of a switching power transistor. The secondary winding is connected in series with the collector-emitter path of a sense transistor which responds to the current flowing through the switching power transistor. The tertiary winding is connected in series with the battery, series-connected batteries or series-connected battery packs sought to be recharged, via a diode, which may be connected in parallel with a capacitor. The battery or batteries are charged by current pulses and discharge through the tertiary winding to repolarize the diode (and capacitor if present). The secondary winding is poled, with respect to the tertiary winding so that the blocking oscillator is driven by energy from the battery or batteries.

Abstract: A multistation charging system is provided for charging batteries within a plurality of cordless tools, appliances or the like, each of which has at least one rechargeable battery therein. A plurality of modules, which act as charging stations, are arranged substantially adjacent to one another. Normally closed pairs of conductive contacts are provided in each of the modules. The electrical pairs of contacts in the modules are connected in a series circuit arrangement with each other. On one of the modules, electrical connection is provided to a single current regulated solid-state charging device which produces charging current pulses. The device may alternatively be in the one module. Each of the modules removably supports a respective tool or appliance and each tool or appliance has means for electrically connecting the respective battery therein within the series circuit arrangement and in series therewith only one wall outlet or a.c. power connection is required.

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 charger for batteries includes a a charging station, which includes a housing. A casing end having an open portion through which batteries to be charged are to be inserted is provided. A constant tension spring within the casing urges the batteries outwardly of the casing. A lid is provided adjacent to the open end of the casing, the lid being movably, pivotably supported on the casing. A stop member is provided on the housing, the stop preventing the lid from being moved to its completely open position when the casing is supported on the housing. A latch arrangement retains the lid in a closed orientation. The batteries in the casing are retained therein by a portion of the lid whenever the lid is pivoted away from its completely open position. Contact means are provided between the housing and casing to provide a path for charging current. A multiple of charging stations can be provided, the multiple stations being electrically and mechanically connected.

Abstract: A direct current pulse producing circuit, which can be connected in series with a battery or battery pack to be charged or recharged, or in series with a smoothing circuit of a D.C. power supply, includes Darlington configured transistors forming part of a current amplifier. The pulse producing circuit can be directly connected in series with the battery or battery pack, or the smoothing circuit across a conventional A.C. 117 volt, 60 Hz. voltage source. The direct current pulse producing circuit may be realized as monolithic integrated circuit, and includes a rectifying diode, one electrode of the rectifying diode being formed by at least part of a substrate upon which the circuit is formed. Circuit components are formed in the monolithic circuit which effect the cancelling of undesired current caused by parasitic transistor action resulting from use of the substrate or a portion thereof as an electrode of a rectifying diode.

Abstract: A multi-station charging system is provided for charging batteries within a plurality of cordless tools, appliances or the like, each of which has at least one rechargeable battery therein. A plurality of modules, which act as charging stations, are arranged substantially adjacent to one another. Normally closed pairs of conductive contacts are provided in each of the modules. The electrical pairs of contacts in the modules are connected in a series circuit arrangement with each other. On one of the modules, electrical connection is provided to a single current regulated solid-state charging device which produces charging current pulses. The device may alternatively be in the one module. Each of the modules removably supports a respective tool or appliance and each tool or appliance has means for electrically connecting the respective battery therein within the series circuit arrangement and in series therewith only one wall outlet or a.c. power connection is required.

Abstract: A battery-operated device having a passive charging mode and an active discharging mode is combined with a support, which supports the device in its charging mode. The support is integral with a plate which is to be positioned on a wall. The plate may be a replacement cover plate which may be substituted for a cover plate of a conventional A.C. wall outlet. The device includes a short power cord having a plug at its distal end. A D.C. current pulse producing circuit, preferably a solid state integrated circuit is housed within the plug. The D.C. current pulse producing circuit is especially useful as a battery-charging circuit.

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 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 charger for batteries includes a housing having an open portion through which batteries to be charged are to be inserted. A constant tension spring within the housing urges the batteries outwardly of the housing. A cover is provided adjacent to the open portion of the housing, the cover being movably, pivotably supported on the housing. A pair of spaced-apart contact prongs are provided, at least one of which is carried by the movable cover, thereby preventing electrical connection to the prongs wherever the cover is moved away from the open portion of the housing. A latch arrangement retains the cover in a closed orientation. The batteries in the housing are retained therein by a portion of the latch whenever the cover is pivoted away from the open portion of the housing. One of the contact prongs is carried by the cover and moves therewith. A solid-state charging circuit within the housing is connected to the other one of the contact prongs.

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.