Ameronics Regencore 4Q and Revoxa 4Q are four-quadrant regenerative DC drives that motor and brake the load in both directions, returning braking energy to the AC line. Engineered as industrial DC motor drive controllers for hoists, conveyors, mixers, and any overhauling-load application.
A regenerative DC drive operates in all four quadrants of the torque–speed plane: it can apply torque in the same direction as motion (motoring) or opposite to motion (braking), in either direction of rotation. This is achieved with a dual SCR bridge that can source or sink current from the motor armature, making it a true bidirectional DC motor drive controller.
How regenerative braking feeds energy back into the system: when the load tries to overhaul the motor, the armature back-EMF exceeds the drive's commanded voltage. The second anti-parallel SCR bridge fires at a phase angle greater than 90°, switching from rectifying to inverting mode. Current reverses through the armature and the drive pumps that current back through the AC mains transformer — the kinetic energy of the load becomes real electrical energy returned to the supply, instead of heat dissipated in a dynamic braking resistor.
4-quadrant operation in plain terms: Quadrant I — forward motoring (positive speed, positive torque). Quadrant II — forward braking (positive speed, negative torque, energy regenerated). Quadrant III — reverse motoring. Quadrant IV — reverse braking. A 4Q regenerative SCR drive transitions between all four states seamlessly, without contactors and without waiting for a braking resistor to cool.
Regenerative vs SCR DC motor drives: a standard SCR DC motor drive (also called a non-regen or 1Q/2Q drive) is the right tool for unidirectional, mostly-motoring loads such as pumps, fans, and extruders. A regenerative SCR drive adds a second thyristor bridge so it can both source and sink armature current, returning braking energy to the line. The trade-off is more silicon, more control complexity, and a higher price — paid back quickly on overhauling loads or high-duty braking. For low-voltage or fractional-horsepower duty, a PWM DC motor controller is usually a better fit than either SCR topology — compare all three families on the main DC motor drive controller page.
Ameronics offers two regenerative DC drives: Regencore 4Q on chassis and Revoxa 4Q enclosed. Both share the same proven SCR-based four-quadrant core, with tach or armature voltage feedback and isolated control inputs.
A 4Q SCR drive uses two anti-parallel SCR bridges so that current can flow either direction through the motor armature, enabling motoring and braking in both directions of rotation without contactors.
When the load overhauls the motor, the second SCR bridge inverts at a firing angle above 90°, reversing armature current and pushing energy back through the supply transformer to the AC line.
Non-regen SCR drives motor in one direction and dump braking energy as heat. Regenerative SCR drives motor and brake in both directions and recover that energy — at the cost of a second bridge.
Four-quadrant regenerative SCR DC drive on a chassis for OEM panel integration.
Same regenerative SCR core as Regencore in a NEMA-style enclosure for stand-alone deployment.
Any application with overhauling loads or frequent rapid deceleration benefits from regenerative braking — both in energy savings and reduced thermal load on the panel.
Send your motor nameplate, supply, and duty cycle — a U.S.-based power electronics engineer will respond with a sized recommendation.
Non-regenerative 1Q/2Q SCR DC drives for unidirectional, mostly-motoring loads.
Learn moreSwitch-mode PWM DC motor controllers for low-voltage and fractional-HP applications.
Learn moreAll Ameronics DC motor drive controllers — PWM, SCR, and regenerative families.
Learn moreSend your specifications or just describe the application — our power electronics engineers will respond with a recommendation.
