Abstract: A medical table having an override circuit includes control circuits for generating control signals in response to user input. Switches are provided for generating control signals in response to user input. Mechanical actuators, responsive to the control signals, move the medical table. An override circuit electrically isolates the control circuits from the mechanical actuators in response to the generation of control signals by the switches.

Abstract: A failure compensation circuit automatically reduces the output voltage of a power supply when a portion of a load drops out. The compensation circuit includes a circuit for generating a control signal representative of the desired voltage across the load. A power supply supplies voltage to the load in response to the control signal. An input signal representative of the current delivered to the load is produced which decreases whenever a portion of the load drops out. The circuit for generating the control signal is responsive to the input signal for adjusting the control signal such that when the current delivered to the load decreases, the voltage delivered to the load is automatically reduced.

Abstract: A compensation circuit includes a circuit for monitoring the current delivered to a load and for producing a switching signal whenever a current spike is detected. A control signal representative of the desired voltage across the load is produced. A power supply supplies voltage to the load in response to the control signal. The circuit for generating the control signal is responsive to the switching signal for adjusting the control signal such that when a current spike is detected the voltage delivered to the load is substantially instantaneously reduced.

Abstract: A battery operated lamp and battery charger are disclosed. The lamp is equipped with a rechargeable battery and a battery charger stand. The lamp has a lamp support surface with a center terminal, and a second terminal spaced from the center which engages the center terminal and second terminal respectively on the lamp. Thus the two lamp terminals will engage the two respective charge terminals regardless of the position of orientation in which the lamp is placed on the charger. The charger circuit is powered from a power cord connected to a power line through a transformer a full wave rectifier to charging lines. These diodes and a switch are connected in parallel with two diodes. The lamp battery to be charged is connected in parallel with the charging lines. Thus, with the switch closed, the charging voltage is reduced to desired value by a voltage drop caused by the resistor and the three diodes in parallel with the battery.

Abstract: Applicant has provided a ballast circuit for fluorescent lights made up of the combination of (1) a source of electrical energy, (2) a resonant circuit, (3) a switch means for connecting the source of electricity to the resonant circuit, (4) means to connect the resonant circuit to a load, (5) a resonant current monitor controlling the switch means in synchronism with the resonant current so that the switch means switches the resonant current when the resonant current passes through zero.The resonant current monitor is a current transformer having a primary winding connected in series with the resonant circuit and two secondary windings connected to the bases of the two switching transistors in a two transistor inverter circuit at a polarity that will switch one of the transistors on and the other off at the time current passes through zero.

Abstract: An inverter ballast for fluorescent lamps utilizing a resonant circuit coupled to the lamp and operated from a source of DC power through transistors. The transistors are controlled by a sensing means in the resonant loop which insures that the transistor switch at zero current. Furthermore, the coupling means for the load controls a source of heater voltage to the anodes of the fluorescent light which operate at very low current, an antisaturation circuit made up of separate windings are on the current transformer and connected to the switching transistor bases and through diodes to the power supply to prevent "shoot through" current in the transistors. An autotransformer is used as a high leakage reactance transformer; and a circuit is provided to prevent overload of the resonant circuit in case of lamp failure. Shoot through currents are prevented, and overload of the resonant circuit is prevented, and an autotransformer coupling of the resonant circuit to the load is used.

Abstract: A spotlight having a generally cylindrical housing with an integral radially extending pistol grip handle at one end, a cord retractor in the rear and a seal beam light closing the open end of the cylindrical housing. The lamp is held in a shock absorbing position by projections on the housing and an integral trigger connected to the housing through a living hinge actuates the switch to turn the light on and off. A trigger lock holds the light "on" and the trigger guard prevents the trigger from being turned on inadvertently. An improved cord holder is provided which utilizes a pinch connection.