Abstract: A circuit for correcting perturbations in a power system signal operating at a system line frequency includes a capacitor for drawing a capacitive current and a first inductor for drawing an inductive current substantially equal in amplitude and substantially one hundred eighty degrees out of phase with the capacitive current. The first inductor is connected in parallel with the capacitor to form a storage module for storing energy therein wherein the storage module is tuned to resonate at the system line frequency and wherein the storage module is connected in parallel across the load. A second inductor connected in series between a power source and the load isolates the power source from the load while a second capacitor in series with the second inductor, which together are tuned to resonate at the system line frequency, prevents voltage drop across the second inductor with linear loads.

Abstract: An apparatus for stunning poultry has a conveyor moving along a predetermined path, for suspending the poultry and a compartmentalized basin defining individual compartments for a conducting liquid. The basin is positioned below a portion of the conveyor. A circuit impresses a voltage across the conveyor and each of the individual compartments. The voltages are a function of the position of each of the compartments relative to the conveyor. The voltages are variable so as to produce a current regulated signal flowing between the conveyor and each of the individual compartments when the poultry is in contact with the conducting liquid in any of the individual compartments.

Abstract: A circuit for correcting perturbations in a power system signal operating at a system line frequency includes a capacitor for drawing a capacitive current and a first inductor for drawing an inductive current substantially equal in amplitude and substantially one hundred eighty degrees out of phase with the capacitive current. The first inductor is connected in parallel with the capacitor to form a storage module for storing energy therein wherein the storage module is tuned to resonate at the system line frequency and wherein the storage module is connected in parallel across the load. A second inductor connected in series between a power source and the load isolates the power source from the load.

Abstract: An apparatus for stunning poultry has a conveyor moving along a predetermined path, for suspending the poultry and a compartmentalized basin defining individual compartments for a conducting liquid. The basin is positioned below a portion of the conveyor and moves at the same speed as the conveyor. A circuit senses the position of each of the compartments relative to a reference point. A circuit, responsive to the circuit for sensing, impresses a voltage across the conveyor and each of the individual compartments. The voltages are a function of the position of each of the compartments. The voltages are variable so as to produce a current regulated signal flowing between the conveyor and each of the individual compartments when the poultry is in contact with the conducting liquid in any of the individual compartments.

Abstract: A high speed transfer switch is provided for transferring a multiphase load among a number of multiphase A.C. power sources. If the initially selected source deviates from desired limits, the transfer switch transfers the load to an alternate source on a phase-by-phase basis. Antiparallel-connected SCRs are used to allow the load current in each phase to commutate to zero before the load is transferred to the alternate power source.

Abstract: Switching of three phase wye power can be efficiently completed without synchronization between two or more energy sources. The absence of synchronism can be overcome by switching one source off and then in a very short time frame restoring the power from the second power source. The duration of the outage can be controlled and minimized so that the load never loses energy long enough to cause an operational problem. The interruption time period in this description is limited to about 100 microsecond span; long enough to avoid interaction between the separate power sources, yet short enough to be transparent to the load. Electrical transfer of loads between power sources may be controlled precisely if the switching is accomplished using solid state electronic devices. Electronic switching is more reliable and does not generate the arcs during transfers that shorten the life span of mechanical contactors.

Abstract: A vectorial neutral is provided in a delta power source. The neutral voltage point is provided by auto-transformers which correct and maintain a near constant voltage in the presence of load or bias currents. With a centered referenced voltage established, full wave rectification of a delta power source is possible.

Abstract: The improved gate drive circuit provides a continuous gate current whenever there is sufficient anode-to-cathode voltage difference across the SCR. This approach described herein eliminates the need to monitor and reapply SCR gate current after each commutation due to load current distortions. Previous SCR gate driver designs used a pulse train of gate currents to provide a means of keeping the SCRs turned on. The pulsed gate control approach has gaps in the SCR's operation and requires significant circuitry that dissipates much more drive energy. Energy for this improved driver circuit is derived from the SCR anode-to-cathode voltage differential. This eliminates the need for individual power supplies to provide isolated gate signals for each SCR. This self-powering feature reduces the intricacy of controlling multiple SCRs in multi-phase or unreferenced power systems. Flexibility provided by this method allows high power SCRs to be directly interfaced to a digital processor-type controller.

Abstract: The invention finds application primarily in three phase power systems having A, B and C voltage phases. The invention includes a first voltage measurement device coupled between the A phase input and the B phase input, having a first measured voltage output. The invention further includes a second voltage measurement device coupled between the A phase input and the C phase input, having a second measured voltage output. The invention also includes a comparator having a first input connected to the first output of the first voltage measurement device and a second input connected to the second output of the second voltage measurement device, for generating a signal when the first measured voltage is equal to and opposite in polarity from the second measured voltage. This signal indicates that a zero crossover event has occurred with the A phase.

Abstract: An asynchronous multiphase switching method and apparatus are disclosed which transfers a system load between two asynchronous AC power sources in an improved manner. It operates as a make-before-break switch to provide uninterrupted power to the system load during the transfer while minimizing voltage and current fluctuations. The control circuitry allows energy to be supplied to the load during the transition without allowing current to flow between the power sources. A matrix of SCRs is used to transfer the load between the two power sources. The switches to be gated are determined by the relative timing relationships of the existing and takeover voltage waveforms. By altering the pattern of the switches which are gated and by controlling the direction of energy flow, the transition can be made between the power sources without interruption of power.

Abstract: A DC power switching circuit connecting a load to a DC power source while suppressing arcing across a relay in the network. A normally open relay has its energizing coil connected to the control input of the circuit, the opposite end of the coil being connected to the gate of a silicon controlled rectifier. The SCR has its principal current conducting path connected between the load and the DC power source, for conducting current between the load and the power source during a first delay interval, thereby reducing the potential difference between the contacts of the relay so as to prevent its arcing during the closure of the contacts. An FET device has its principal current conducting path connected between the load and the DC power source and has its gate connected to a timer.

Abstract: A DC arc suppression circuit is disclosed for suppressing arcs which occur across a mechanical switch or circuit breaker. Several embodiments are described which employ a bipolar transistor to actively shunt the load current around the mechanical switch when the contacts are opened for a period of time long enough to enable the contacts to be separated by a sufficient distance to prevent arcing. Arcing is prevented when contact bounce occurs upon closure of the contacts, by providing a diode connected in parallel with the base-emitter portion of the circuit which restores the arc suppressing capacity of the circuit almost immediately upon the first closure of the contacts.