This was a compound motor with regenerative brakes.

Cumulative compound motors connect the series field to aid the shunt field, which provides higher starting torque but less speed regulation.

DC compound motor (two configurations):

For maintenance of the DC compound motors, it is necessary to inspect and maintain the brushes, so each motored car has access hatches in the floor of the car.

The Compound muscle action potential (CMAP) or Compound motor action potential is an electromyography investigation (electrical study of muscle function).

Two EMG investigations can be characteristic in LEMS: compound motor action potentials (CMAP) and single-fiber examination.

In electrodiagnostic testing with nerve conduction studies, there is a normal compound motor action potential amplitude distal to the lesion at day 10, and this indicates a diagnosis of mild neuropraxia instead of axonotmesis or neurotmesis.

Supraximal electrical stimulation and measurement of conduction velocity and amplitudes of compound motor (CMAP) and sensory (SNAP) responses provide measures of the number and conduction velocities of large myelinated fibers.