A signal monitoring device useful to monitor power consumption level employs a phase locked loop and an associated frequency reduction circuit to convert relatively low frequency input pulse signals to an output signal representative of power consumption.

A power connector for a printed circuit board comprises a plastic body and a conductive plate disposed on the top surface thereof. Conductive pin contacts pass through the body and are attached by solder to the conductive plate. The pins connect to the printed circuit board and a power lead may be coupled to the conductive plate by a screw.

The present power supply has two step-up transformers with their respective primary and secondary windings series-connected. A half-wave rectifier tube and a filter are connected to the transformer secondary windings to rectify the current induced in them and to smooth out fluctuations in that current. One or more additional step-down transformers are provided, each having a primary winding that may be switched in series with the first-mentioned primary windings or disconnected from them and a s...

A power amplifier comprises: a complementary symmetry push-pull circuit formed with two complementary transistors mutually coupled at their emitters and having an operating point for Class-A mode operation; a floating power supply having a neutral terminal serving as the output terminal of the power amplifier, a positive and a negative terminal connected respectively to the collectors of the respective transistors; a bootstrapping circuit for driving the mutually coupled emitters in proportion t...

A high torque hydraulic power plant is operated by electrical power through the use of a hydraulic pump, opposing double-ended cylinders containing double-ended pistons and appropriate cycling valve means. Pressure is maintained in the system by a constant pneumatic force applied to the full piston side of each opposing double-ended piston.

A power hammer having an elongated hammer element disposed in a tubular housing for reciprocating motion therein and having a cylindrical cam concentrically mounted with respect to the tubular housing for displacing the hammer element against the force of a compression spring. When a point in the cam profile is reached which drops off abruptly, the hammer element is driven against an anvil member also disposed in the tubular housing. The cam is adapted to be driven by either an electric motor or...

A power tong system for engaging or disengaging threaded pipe sections has an annular rotary member that is supported against lateral thrust and include a hinged portion that is pivotable to permit side access to a pipe. The rotary member is rotated about its central axis by a peripheral drive chain engaging the rotary member through a relatively small wrap angle. The free end of the hinged portion and the opposing end of the principal body of the rotary interlock and become more secure in self-...

A hydraulic control system comprising a hydraulic actuator having opposed openings adapted to alternately function as inlets and outlets for moving the element of the actuator in opposite directions and a variable displacement pump with loading sensing control for supplying fluid to said actuator. A meter-in valve is provided to which the fluid from the pump is supplied and a pilot controller alternately supplies fluid at pilot pressure to the meter-in valve for controlling the direction and dis...

A power controller having a plurality of power output modules which can be added or removed as desired to change the power output rating. The electrical output of the individual power modules are removably attached to an output combining structure. The electrical connections to the output combining structure also provide mechanical support for the power output modules. The servo controller is constructed so that as additional power modules are added, each provides a predetermined proportion of t...

The amplitude of the rectified voltage applied to the filter capacitor of a power supply is varied by selecting different taps in the secondary winding as a function of the output voltage and current so that the supply provides a wide range of operating voltages and currents in a minimum volume and at reduced cost.