Abstract: A protection circuit for the power transistor of an automotive motor control circuit. The protection circuit comprises a protection transistor, a resistor, and a Zener diode. The emitter-collector circuit of the protection transistor is connected in series with the resistor across the primary conduction path of the power transistor, with the resistor connected across the conduction control terminals of the power transistor. The Zener diode is connected in series with the emitter-base circuit of the protection transistor across the motor, with the Zener diode poled to oppose current flow through the emitter-base circuit. Transient inductive voltage generated across the motor upon removal of an externally applied control signal exceeds the reverse breakdown threshold of the Zener diode and biases the protection transistor conductive.

Abstract: A control unit for operating the motor of a motor driven headlamp carrier mechanism includes oscillator circuitry for generating a series of pulses for energizing the motor, voltage responsive means for sensing a motor counter-EMF related voltage as an indication of motor rotation, output circuitry for interrupting motor energization when the voltage responsive circuitry senses motor stall, and start circuitry for energizing the motor independent of the oscillator circuitry for a period of time sufficient to produce motor counter-EMF. Such control permits sensing of the engagement of the headlamp carrier with fixed mechanical stops without the use of position or torque limit switches.

Abstract: A concealable headlamp assembly and an actuator therefor that provides an increased force output for moving the headlamp assembly from the concealed position to the exposed position when opening movement of the headlamp assembly is resisted.

Abstract: A nonglare rear view mirror assembly includes a combination diaphragm and bellows and a front transparent lens on the bellows defining a variable volume chamber of opaque liquid rearwardly of the transparent lens. A light reflective mirror is connected to a plurality of bosses on the diaphragm to define a liquid pump chamber in communication with the variable volume chamber. The diaphragm is associated with a rigid cover to define a variable pressure space selectively connected to a source of power fluid to flex the diaphragm to direct opaque liquid from the pump chamber into the variable volume chamber behind the lens for producing a nonglare light reflection under night operation and operative under daylight conditions to flex the diaphragm to draw liquid from between the lens and mirror to locate the mirror adjacent the lens for producing greater light reflectivity.

Abstract: A headlamp with a parabolic reflector has a filament mounted on lead wires attached to a support disc which is slidably and angularly adjustable within a cylindrical ferrule attached to the reflector so as to permit positioning the filament at the reflector focal point whereupon light from the filament will be reflected as a parallel beam from the reflector. The invention contemplates an improved method for focusing the filament including locating a planar mirror on the optical axis of the parabolic reflector for redirecting light parallel to the optical axis from the reflector back to the focal point of the mirror and wherein terminals of the filament are electrically connected to a power supply and to a meter to detect electrical resistance changes in the filament to indicate location of the filament at the focal point where light rays reflected from the flat planar mirror directly impinge on the filament to cause increase in its electrical resistance.

Abstract: An incandescent lamp has an envelope defining a sealed fill gas cavity in which is located an electrically energizable tungsten filament that, when energized, has a sheath formed therearound of nonreactive gas and vaporized tungsten to suppress filament evaporation; the gas fill further includes a small quantity of helium in the range of 1% - 6% of the total gas charge effective to increase the density of the sheath and to increase temperature gradient within the sheath thereby to produce a drive force that improves the redeposition of tungsten vapor from the sheath back to the filament thereby to increase bulb life.