Abstract: In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system, consistent with the present disclosure, includes a power feed branching unit (PFBU) having a multi-port DC/DC converter (DDCM) arrangement capable of a plurality of operating modes to distribute power in a bi-directional manner. The DDCM arrangement may include a plurality of ports for electrically coupling to one or more trunk path cable segments and for electrically coupling to a branch cable segment. A plurality of PFBUs may be disposed along a trunk path, with each PFBU powering an associated branch path, without each branch path necessarily having local power feed equipment (PFE). In instances where a branch path includes a local PFE, an associated PFBU may draw power from the branch path in order to make power available to the trunk path as needed.

Abstract: In general, a branching configuration used in a wavelength division multiplexed (WDM) optical communication system, consistent with the present disclosure, includes a power feed branching unit (PFBU) having a multi-port DC/DC converter (DDCM) arrangement capable of a plurality of operating modes to distribute power in a bi-directional manner. The DDCM arrangement may include a plurality of ports for electrically coupling to one or more trunk path cable segments and for electrically coupling to a branch cable segment. A plurality of PFBUs may be disposed along a trunk path, with each PFBU powering an associated branch path, without each branch path necessarily having local power feed equipment (PFE). In instances where a branch path includes a local PFE, an associated PFBU may draw power from the branch path in order to make power available to the trunk path as needed.

Abstract: An optical gain block that is pumped by one or more pump input modules is disclosed. Each pump input module includes a pump source, a pump power control circuit and a bus interface. Each of the available pump input modules detect the presence and pump power of other available pump input modules in order to properly adjust the output power of its own pump source. By controlling the power provided by each of the available pump input modules, the gain block output will be maintained at a specified output power level while all pump input modules share in delivering the required total input pump power. Upon the insertion or removal of any pump input module, the remaining pump input modules will adjust their output power accordingly to maintain the gain block output power at the specified level.

Abstract: A motor protection circuit which generates a signal having a value proportional to the magnitude of the input current of the motor and a motor speed signal having a value proportional to the difference between the rated motor speed and the actual motor speed. The motor speed signal is multiplied by the input motor current proportional signal to derive a product signal. The product signal is summed with the input motor current proportional signal to derive a sum signal. The sum signal is compared with respect to a preset level to determine if it is greater than a preset level. If it is greater than a preset level, the sum signal is coupled to the input of a voltage controlled oscillator which generates an output signal having a value proportional to the magnitude of the sum signal. The output of the voltage controlled oscillator is counted in an up/down counter and an output is gated when the total count reaches a predetermined level.

Abstract: A transistor having a selectively saturated emitter collector path is protected.The emitter collector voltage level is sensed as being greater than a predetermined level to indicate saturation as is the presence and absence of drive current to the base. In response to the transistor not being activated to saturation while the drive current is applied to the base, a fault indication is derived. In response to the fault being indicated, the transistor is prevented from conducting by decoupling a source of operating voltage and current from the emitter collector path and/or decoupling the drive current from the base.

Abstract: A voltage snubber connected to the output terminals of a transistorized, push-pull inverter for supplying bidirectional current to an inductive load comprises a snubber capacitor and relatively large valued resistor connected in series with each other across the output terminals of the inverter and a switching circuit for bypassing the resistor during turn-off periods of the inverter transistors. The value of the snubber resistor is high enough to provide slow recharging of the snubber capacitor during turn-on periods of the inverter transistors to reduce transistor power dissipation. When the resistor is bypassed by the switching circuit during the inverter transistor turn-off periods, the snubber is gated on to suppress high voltage surges generated by the inductive load. The snubber switching circuit is responsive to current sensors or logic commands connected in circuit with the inverter to detect turn-off transistors of the inverter transistors.