Abstract: The present invention relates to a gamma radiation detector probe with Geiger-Muller tube of the type which compensates for pulse losses of the Geiger-Muller tube due to dead time and linearizes its response to the number of pulses per unit of time in relation to the gamma radiation exposure rate, including a converter of the electric current from the Geiger tube into a current-dependent pulse frequency, an element for combining or mixing these pulses with those supplied by the Geiger tube, and logarithmic networks for adjusting the frequency of the converter in order to linearize the response of the complex.

Abstract: A normally OFF linear bilateral switch using two VMOS FETs is described. The conduction state of the two VMOS FETs is controlled by a photodiode array optically coupled to a light emitting diode. A break-before-make switch may be constructed using this switch together with a normally ON JFET.

Abstract: A method and apparatus of inspecting a surface of a specimen for the presence of defects, foreign substance and the like are disclosed. The surface has a mark such as a cutting mark formed thereon and composed of fine grooves or recesses extending in a predetermined direction. The surface is scanned two-dimensionally with an irradiating laser beam impinging or illuminating on the specimen surface perpendicularly thereto. Those of the irregularly scattered laser light rays reflected from the specimen surface which are in a first direction perpendicular to the lengthwise direction of the mark are intercepted by a shielding member or caused to pass through regions other than a reflecting region of a reflecting mirror, while those scattered light rays which are in other directions than the first direction are directed to a photoelectric converter tube along a bypass path across the shielding member or through reflection of the mirror.

Abstract: Combustion of fragmented slow-burning solid fuel, such as wood fragments, in the combustion chamber of a portable combustion receptacle or pressure vessel mounted on the rear of a hybrid vehicle, is initiated by igniting in the combustion chamber combustible starting fluid gas, such as propane gas from an external source and ignited by a glow plug. Air is supplied by an air compressor driven by a prime mover such as a turbine or electric motor. As soon as combustion of the solid fuel has become self-sustaining, the supplying of this starting gas is terminated. Meanwhile, the pressurized gas emitted from the burning solid fuel in the combustion receptacle is discharged into a power turbine by way of a controlled throttle valve. The output shaft of the turbine drives a speed-reducing transmission which in turn drives an alternator of my electric vehicle propulsion system identified herein.

Abstract: The horizontal axis wind turbine converts wind into electrical energy and includes a pitch control vane with a flyweight mechanism on each rotor blade to provide aerodynamic efficiency at operating wind velocities, near constant speed and zero lift pitch of the rotor blades when speeds exceed the design speed of the system. A gravity neutralization means composed of a bevel gear and pinions couples the blades together while a flyweight arrangement connected to the bevel gear acts to neutralize centrifugal torque on the blades.

Abstract: Set out herein is an electrical generator conformed for installation in a buoy, the generator comprising an inverted pendulum having two windings formed at the free end thereof and aligned to articulate between two end stops each provided with a magnetic circuit. As the loops thus pass through the magnetic circuit, electrical current is induced which may be rectified through a full way rectifier to charge up a storage battery. The buoy itself may be ballasted to have its fundamental resonance at more than double the wave frequency with the result that during each passing of a wave at least two induction cycles occur.

Abstract: A residential energy controller includes a first bi-metal element having a free end and a stationary end. A second bi-metal element has a first end connected to the free end of the first bi-metal element. The second bi-metal element is included in a thermostat that controls an air conditioning apparatus for cooling the residence. A sensing device senses current delivered to the residence and produces a corresponding sense current. The first bi-metal element is electrically resistive. The sense current is forced through the resistive material of the first bi-metal element, causing it to be heated to a temperature that is related to the amount of power being delivered to the residence, thereby causing the free end of the first bi-metal element to rotate and causing the entire second bi-metal element to rotate. This causes the turn-on temperature of the thermostat to be increased by an amount related to the total power being delivered to the residence.

Abstract: An electromechanically controlled switch assembly including an automatic, three position, removable, transfer switch and a three position, manually operated bypass switch assembly. Electromechanical controls are utilized to sense the position of both switches, including whether or not the bypass switch is being manually switched to the normal or an emergency source of power, whether or not the power sources are available, and whether or not the transfer switch is properly located within its supporting frame for normal operation, completely isolated, or isolated from the load but in the correct location for testing.

Abstract: A gating circuit for a universal counter comprises a pair of flip-flops and a pair of logic gates arranged to provide any of a plurality of counting or timing measurements. A gate control circuit includes a control logic unit to provide routing and synchronization of digital signals from several inputs, including an internal source as well as a pair of external sources, into one or both of a pair of count chains.

Abstract: A single shot multivibrator comprising two inverting OR circuits connected in closed loop configuration by a cascaded series of delay elements some of which are partially bypassed at selected locations so as to reduce the recovery time of the multivibrator. The delay elements comprise one or more inverting OR circuits positioned at the selected locations with the remainder being simple inverting circuits. Although the output pulse width of the multivibrator is determined by the total delay of the cascaded units, the recovery time is made a fraction thereof, depending upon the number and the locations of the bypasses.

Abstract: A majority logic gate is comprised of a plurality of depletion mode switching devices and includes Schottky diodes for both level shifting and clamping the high logic level output voltage to ground. A plurality of MESFET input devices each have their gate electrode coupled to one input of the majority logic gate. Each MESFET input device has a source coupled to ground and a drain coupled to a current load device. The voltage level at the drain at each of the input devices changes from a logical "0" to a logical "1" state depending upon the number of inputs which are at a logical "1" level. The drain voltage is then level shifted down. The high logic level output voltage is clamped to ground by means of two Schottky diodes the first of which has a cathode coupled to ground and an anode coupled to the anode of the second diode, the cathode of the second diode being coupled to the output of the circuit.

Abstract: A sense amplifier having a conventional three transistor network for charging a column to a first predetermined voltage uses a depletion transistor to charge the column beyond the first predetermined voltage for detection of a memory cell which is in a non-conducting state. A memory cell in a conducting state draws enough current to prevent the depletion transistor from charging the column beyond the first predetermined voltage. A logic "1" is detected when the column charges beyond the first predetermined voltage to at least a second predetermined voltage, whereas a logic "0" is detected when the column does not reach the second predetermined voltage.

Abstract: A high frequency inverter power supply having isolation between the drive circuitry and the Power Switching device and utilizing a Field Effect Transistor as the Power Switching device is described. Circuitry for rapidly charging the gate capacitance of the Field Effect Transistor for enhancing the rate of its switching to the conductive state and for rapidly discharging the gate capacitance for enhancing the rate of its switching to the non-conductive state is shown.

Abstract: The stepping motor (1) is provided with magneto-mechanical means (11) in order to reverse the rotation sense of its rotor (2). When the magnetic element (12) is withdrawn or flush with the gap (3), the rotor turns in the sense of the arrow (27). When such element is extended into the gap through application of pressure to the push-piece (14), the rotor will turn in the sense opposite to that of the arrow (27).

Abstract: In the disclosed system, the stator of a motor is provided with a plurality of radially directed stator poles, each having stator teeth arranged in a circle around an axis, and includes permanently magnetized rotor teeth facing the poles. The number of poles on the stator is sixteen at regular intervals of 221/2 degrees, each having teeth offset from the teeth on the poles 90 degrees therefrom by one full pitch and offset from the teeth on adjacent poles by one-quarter pitch. According to an embodiment, the coils are energized digitally to move the rotor at one-half, one-quarter, one-eighth, one-sixteenth, and one-thirty second steps. According to another embodiment, the poles are spaced and shaped to permit large preformed windings to be mounted thereon.

Abstract: A liquid-cooled eddy-current coupling device is disclosed, having a field coil and rotatable inductor and rotor members within a housing, with the rotor member having a tubular extension with an exterior circumferential groove disposed to direct liquid coolant away from the field coil.

Abstract: A magneto flywheel includes arcuate ceramic magnets of non-uniform radial thickness. A rotor for the flywheel is made of soft material. The magnets of the magneto flywheel have a set of radial poles of alternating polarity, and an other set of opposite poles directed toward the cylindrical periphery of the magneto rotor. A ferromagnetic band of deflectible material with the surface projection is disposed between the rotor and the magnets.

Abstract: A safety device for preventing overspeed of a rotary shaft driven by an electrical motor is arranged to cut a portion of an electrical circuit feeding the motor with electrical power, by making a cutter received in a rotary member jump up or protrude by a centrifugal force acting on the cutter, so that dangerous overspeed is prevented. The cutter is movably received in a radial bore made in the rotary member, and receives a tensile force from a coil spring which is fixedly supported by the rotary member at one end of the spring. An adjusting screw, which is a cylindrical member, is provided for biasing the cutter against the tensile force from the spring. A critical rotational speed, above which the cutter jumps to break the electrical circuit, can be freely adjusted by changing the position of the adjusting screw. The change in position of the adjusting screw results in both the change of an eccentric distance of the cutter and the change of the tensile force of the spring.

Abstract: An electrically actuated positioning element system utilizes a positioning element formed of piezo-electrical bodies each formed of a plurality of lamellae having electrodes. The lamellae have a length substantially greater than their thickness and upon application of an electrical voltage with a field direction which promotes a polarization of the material of the lamellae, the body is shortened. The two bodies are connected to one another at one end by a cross arm and at the other end the one body end is active and free to move relative to the other body end such that a resultant relative motion occurring between the two body ends may be utilized. Preferably a connection is provided for absorbing a lateral thrust of the bodies. The two piezo-electrical bodies are each electrically connected to one another for reverse-phase operation such that one contracts while the other is in a lengthened condition and vice versa.

Abstract: A lamp assembly comprises a high pressure discharge lamp and reflector wh are secured together as a structural unit. An insulating base is connected to the neck end of the reflector and to the lamp, and a front end ring is connected to the front, light emitting end of the lamp and reflector assembly. A pair of electrical connection members, preferably in the form of pins, are associated respectively with the base and end ring and are rigidly connected to the respective associate base and end ring. The connection members are electrically connected to respective ends of the lamp, the lead-in wire of the lamp and the front or light emitting end of the structure extending from the lamp substantially radially to at least one of the reflector and end ring and then extending directly to the connection member associated with the end ring. Preferably, the lead-in wire at the front end of the structural unit acts as a support and adjustment or locating member of the lamp.

Abstract: A green light-emitting fluorescent material prepared from terbium-activated lanthanum cerium orthophosphate expressed by the structural formula:La.sub.x Tb.sub.y Ce.sub.z PO.sub.4where:x+y+z=10.05<x<0.350.05<y<0.30.6<z<0.9and a fluorescent lamp comprising said green light-emitting fluorescent material used alone or in combination with any other form of fluorescent material.

Abstract: In a fluorescent lamp of the type in which a lamp envelope comprises an outer bulb having generally a spherical or a partially spherical or a cylindrical configuration and an inner bulb inserted into the outer bulb in predetermined nested relationship; either of the inner surface of the outer bulb or the outer surface of the inner bulb is formed with a groove which defines a zig-zag discharge path between the outer and inner bulbs; a phosphor is formed at least over the wall surfaces of the groove; electrodes are disposed at the ends, respectively, of the discharge path and a uv (ultraviolet) radiation-emitting discharge gas consisting of mercury vapor and a rare gas or a rare gas mixture is filled in the discharge path, both the open end portions of the outer and inner bulbs are flared radially outwardly and inwardly respectively, or either of the open end portion of the outer or inner bulb is flared radially outwardly or inwardly so that glass frit can be filled into the annular space defined between the op

Abstract: A vacuum container of a radiation image multiplier tube is disclosed, which is provided with a radiation input window made of Al or an Al alloy and an output portion made of a glass or ceramic insulator for outputting radiation image multiplied signals. Between the input window and the output portion is interposed a ring made of Fe or an Fe alloy, and an airtight joint between the ring of the input window is effected by hot pressure-bonding through a thin layer of Ni, Cu or Al. A method of manufacturing the vacuum container by means of such hot pressure-bonding is also disclosed.

Abstract: Disclosed is a panel type display apparatus comprising a back plate and a transparent front plate, these plates facing each other at a small distance. A plurality of parallel strip-like cathodes are formed on the inner surface of the back plate facing the front plate and extend in a first direction. An insulating rib structure is formed on the inner surface of the back plate and has a lattice-like structure that extends along lines between adjacent cathodes in the aforementioned first direction and also along lines extending in a second direction at right angles to the first direction and defines a number of display element sections. A plurality of anodes are formed at least one portions of the rib structure extending in the aforementioned second direction. These anodes are formed on one side of portions of the rib structure extending in the second direction for the display element sections defined on the aforementioned one side.

Abstract: A high-pressure sodium lamp in which the ends of an arc tube which is made of transparent single-crystal alumina and which contains sodium are sealed with feed-throughs each having an electrode extended from the inner end thereof.Each feed-through is directly sealed to the inner wall surface of each end of the arc tube. In addition, each feed-through is formed with an enlarged-diameter portion which is directly sealed to the inner wall surface at each end of the arc tube and a reduced-diameter portion which is spaced apart from the inner wall surface at each end of the arc tube.

Abstract: A controlling electrode is positioned in physical proximity to one or more electrodes in an electron beam tube so that the controlling and controlled electrodes are subject to common electron bombardment. A control voltage of preselected magnitude and polarity is applied to the controlling electrode. During the common electron bombardment, primary and secondary electrons are present in the region of the electrodes, an exchange of electrons occurs between the electrodes, and the voltage on the controlled electrodes switches to a value at or near the voltage applied to the controlling electrode. The electron beam tube can be a cathode ray pin tube used in electrostatic printing in which case a single controlling electrode is positioned in proximity to the array of conductive pins in the tube face plate.

Abstract: An ion generating apparatus comprises a cylindrical vacuum vessel within which an anode and cathodes are disposed. The anode is provided with an inner tubular hollow portion and the cathodes are located near both end openings of the anode. The apparatus further comprises means for applying a voltage between the anode and the cathodes, a magnetic field generator, means for supplying operating gas into the hollow portion of the anode, and an evacuating device. At least one of the cathodes is provided with a through hole at the central portion thereof. The apparatus further comprises a control electrode stretched in the hollow portion in parallel with but apart from the central axis of the hollow portion.

Abstract: An AC memory driving type self-shift type gas discharge panel prevents accidental abnormal discharges caused by deviated abnormal charges. Abnormal charges are significantly accumulated at both ends of a shift channel consisting of a regular arrangement of a write discharge cell and shift discharge cells. Therefore, conductive layers are provided adjacent to at least both ends of the shift channel in order to dissipate the abormal charges.

Abstract: Three-transistor, four-terminal precision current source is switchable. Current is passed between two of the terminals in the presence of a switching signal on another terminal. While switched on, the current is regulated according to a reference voltage supplied to the remaining terminal.

Abstract: In a television display system, a deflection yoke is placed over the neck of a cathode ray tube to generate a raster by means of simultaneous horizontal and vertical sweep of the electron beams. A picture, derived from information contained in the composite video signal produced by the signal processing circuits, is displayed on the screen of the cathode ray tube. In the horizontal deflection circuit portion of the television display system, a trace capacitor is coupled to a deflection winding. A trace switch, responsive to a deflection rate signal that is synchronized with the composite video signal, periodically applies to the deflection winding the voltage developed across the trace capacitor to generate raster scanning current in the deflection winding during a deflection cycle. The losses incurred during a deflection cycle tend to produce a scanning current waveform that introduces asymmetrical linearity distortion to the picture display.

Abstract: An electric motor for a magnetic tape recorder comprises an electrically insulating disk-shaped stator with a plurality of flatwise coils, a rotary shaft rotatably extending through the stator, and a first disk-shaped rotor of soft iron with a multi-pole annular magnet and a second disk-shaped rotor of soft iron rotatably extending through the shaft on both sides of the stator. A pulley is fixed on the shaft below the first rotor to drive capstans, and a reel disc or a pinion is coaxially connected to the second rotor to drive a take-up reel for forward play. In a fast forward feed mode, the first and second rotors can be mechanically interlinked. Alternatively, an electromagnetic solenoid may be used to take out a torque from the first rotor by engaging an idle roller with a roller fixed to the rotary a shaft above the pinion or to apply a pressure to the second rotor to increase the friction between the second rotor and an adjacent shoulder on the shaft.

Abstract: Device for synchronizing two asynchronous rotary field motors, the output of said motors being via reduction gears connected to the movable parts of synchronizers of for instance the selsyn type, said synchronizers being connected to generate a correction signal dependent on direction and value of a positional difference between the said movable parts, said motors being controlled by a frequency converter the output frequency of which is controlled by an electrical input, at least one of said inputs being combined with said correction signal, R.C.-circuits controlling the time function of the said electrical inputs.

Abstract: A drive means comprising a movable part and a fixed part provided with a stator winding and a magnet yoke with a magnetic gap. A soft-iron magnetic portion is arranged in the magnetic gap. A current generator generates a first current for a stator winding and a second current for another stator winding, the sum of the magnitudes of the two currents being constant. The reluctance effect causes each of two soft-iron magnetic portions to be pulled into an individual magnetic gap driven by one of the two currents. The two reluctance forces vary quadraticly with the two currents, but due to the fact that the net force is the difference between them, this net force will be linearly dependent on the currents. It is suitable to allow the two currents to come from the same amplifier stage, which is push-pull coupled.

Abstract: A control system for a separately excited DC electric traction motor in an electrically powered vehicle incorporates a plurality of current limit functions designed to protect both the motor and control electronics. A time dependent current limit is utilized to permit overcurrent conditions for limited time intervals such that additional power can be obtained for sudden torque requirements without having to design the motor or control electronics to function under continuous high torque conditions. The continuous current limit values based on percent conduction time of a thyristor chopper circuit in the control system is modified in response to overheating of the motor and the main switching thyristor, to overvoltage on the thyristor commutating capacitor and to available voltage for powering the motor.

Abstract: An electrical braking circuit provides smooth transitioning between regenerative and plug braking of a DC electric motor by use of a low ohmic value resistance path to maintain motor torque during transitioning. During initiation of electrical braking, a similar low ohmic resistance path momentarily connects the motor to a power source in order to establish proper magnetic flux in the motor to enable regenerative braking. Both resistance paths are disabled during motoring and braking modes of operation in order to minimize power loss in the resistance paths.

Abstract: An electric damper motor drive with a backup power pack is disclosed comprising a reversible electric motor operable in first and second opposite directions in response to first and second distinct forms of electrical energization, respectively. A primary power source normally supplies electrical power to energize the motor in response to a sensed environmental condition. A backup power pack is responsive to the absence of power from the primary power source to supply the first form of electrical energization to drive the motor in the first direction to a predetermined position.

Abstract: The disclosure describes a digital servo control circuit to actuate an analog servo motor smoothly from an actual present position to a new desired servo position in response to digital information from a computer. The control circuit described receives from a computer digital information representative of a new position desired at a predetermined velocity rate. Such information normally is pre-timed to correspond with a preselected timing rate in the digital computer. A position signal generator is responsive to such pre-timed digital information to generate a predetermined number of position signals intermediate of the pre-timed digital information to achieve the desired smooth operation of the servo motor.

Abstract: A stepper motor controller circuit is described. The circuit comprises four power transistors configured to drive current in either direction through a stepper motor winding. A series resistor senses instantaneous current and a chopper is used to limit this current to some predetermined maximum value. Eight diodes protect the circuit against reverse, current surges, and a flip-flop guarantees a minimum duty cycle.

Abstract: Apparatus is disclosed wherein parameter values for the stator resistance, the main inductance and the stray inductance of an asynchronous machine is detected without using information about the rotor position. Thereby the apparatus consists of an EMF-forming circuit, an arithmetic control circuit, an arithmetic model circuit, and a control circuit. All circuits are coupled to form an overall model circuit designed according to a closed loop circuit to simulate the operational conditions of an asynchronous machine. In a balanced position of the control circuit the output signals of the control circuit represent the actual parameter values to be determined.

Abstract: An automobile is provided with a wind driven electric generator. An air duct extends from an inlet along the roof section of the body above the windshield and over the passenger compartment to air outlets located in the fender wells of the automobile rear section. Air turbines, operatively connected to electric generators, are positioned at the air outlets and are driven by air currents flowing from the duct.

Abstract: A complementary field effect transistor integrable voltage regulator suitable for use in CMOS integrated circuits includes first and second regulator sections coupled together. One regulator section includes a P channel MOSFET and an N channel MOSFET and a resistor, the P channel MOSFET and the resistor being coupled in series between an internal supply conductor and a reference conductor, the N channel MOSFET being connected in parallel therewith and having its gate electrode connected to the junction between the P channel MOSFET and the resistor. The gate electrode of the P channel MOSFET is connected to the output of another regulator, which includes a zener diode and a resistor coupled in series between the reference conductor and another voltage conductor.

Abstract: Circuit for generating a d-c output voltage being independent of fluctuations of a d-c supply voltage, including a reference voltage circuit connected to a d-c supply voltage source, the reference voltage circuit including a series circuit of a constant-current source and a potenatial shift branch, an inverting amplifier being connected to and addressed by the reference voltage circuit, the inverting amplifier having an output circuit including a combination of a plurality of first resistors and at least one first transistor determining the gain of the inverting amplifier, an output driver supplying the d-c output voltage, the output driver being connected to and addressed by the inverting amplifier and the output driver having an output circuit being connected to the potential shift branch of the reference voltage circuit for driving the potential shift branch, the output driver including an emitter follower stage having an output circuit with a second transistor and a second resistor, a voltage stabilizing

Abstract: An impedance measuring apparatus having a measuring transistor with its gate electrode adapted to form a two electrode, interdigitated capacitor with the material to be measured forming the dielectric, a second reference transistor connected in differential configuration to the measuring transistor so that their drain currents are constrained to be equal, a time-varying voltage generator connected to one electrode of the interdigitated capacitor and a gain-phase meter connected to the gate of the reference transistor.

Abstract: An instrument for monitoring the hazard arising from electro-magnetic (electric and/or magnetic) radio-frequency fields comprising an electric and/or magnetic field probe, a radio-frequency converter for converting the signals picked up by the probe into continuous current electric signals, a comparator for comparing the continuous current electric signals with predetermined reference values, and output indicators activated by the output signals of the comparator. Preferably the reference values divide the values of the field levels into three contiguous zones, respectively-of insignificant risk, of possible risk and of certain risk.

Abstract: A test probe having only two substantially rigid electrically conducting members which are insulated from each other, these members terminating in respective contact portions. When the probe is in use, these two contact portions simultaneously contact spaced apart areas of a current conducting segment then being tested. An insulated handle is formed by a protecting layer of insulation coupled to the two conducting members; and a pair of conducting leads pass through the handle and are electrically connected to the respective conducting members. In a preferred embodiment, the two conducting members are constituted by a cylindrical shaft which is longitudinally bisected into separate longitudinal portions that are bonded to each other by a layer of insulating adhesive. The cylindrical shaft terminates in a conical contact tip which also is longitudinally bisected, the two bisected portions of this tip constituting the contact portions of the probe.

Abstract: An unbalanced current detector for a three phase electrical system of the type including a current transformer (4, 6, 8) for each phase (.phi.A, .phi.B, .phi.C) and a burden resistor (16) which receives a rectified output of the current transformer is disclosed. The harmonic content of a rectified ripple voltage developed across the burden resistor (16) is applied to a filter (20) for extracting desired frequencies and rejecting other frequencies, and the filter output is applied to a level detecting and amplifying circuit (54) the output of which is applied to an indicator (77) to indicate an unbalanced current condition.

Abstract: The present invention is for an induction meter having a voltage and a current magnetic section. The voltage magnetic section is comprised of a substantially E-shaped laminated magnetic core having a center leg terminating at a main pole face and two adjacent legs terminating at coplanar auxiliary pole faces on opposite sides of the main pole face, and includes a spacer bracket located between a first side of the voltage magnetic core and a first voltage shunting member. The spacer bracket carries a self-aligned, light load adjustment assembly having a movable tab extending over portions of one of the auxiliary pole faces and the main pole face thereby providing an adjustable magnetic flux shunt path. A second voltage shunting member is located in magnetic proximity to the first side of the core and spaced from the first voltage shunting member by a nonmagnetic spacer.

Abstract: An electrical probe assembly with rotatable probe elements for establishing electrical contact to pad surfaces having a plurality of elongated probe elements formed of a conductive flexible material, each having a length many times its diameter, spaced upper and lower flat support elements having apertures receiving the ends of the probe elements and maintaining the probe elements in a generally parallel arrangement with at least the lower ends in a configuration corresponding to the pad configuration to be contacted, and a means to simultaneously rotate the probe elements.

Abstract: A metal detector is disclosed which has a transmit coil, a receive coil, and circuit means for detecting metal object due to a change in the magnetic coupling between the coils. Circuit board arrangement techniques are disclosed which enable the close placement of the transmit and receive coils and the circuit board, thereby allowing packaging of the metal detector in a small package. A low battery voltage indicator circuit is provided to warble an audio indicator signal to indicate sufficient battery voltage. In the event the battery voltage drops below a certain level, the warbling of the indicator signal ceases and a steady tone is generated thereby indicating a low battery voltage condition.

Abstract: The condition of a storage battery of an internal combustion engine powered vehicle is tested automatically, and an indication of battery condition is provided to the service technician. The battery testing apparatus is connected to the positive (+) and negative (-) terminals of the battery to measure battery voltage under several different conditions. In particular, the battery testing apparatus measures battery voltage under open circuit conditions, while subjecting the battery to a predetermined AC load, and while subjecting the battery to a predetermined DC load. The battery testing apparatus also includes a temperature probe which measures the temperature of the battery.