Alternators and electro-hydraulic regulation: status update with C.G.E. (23 February 1961)

In this document

These two pages are handwritten notes by Paul Magès, dated and precisely timed: "23.2.61 11:55", written during a meeting with Mr. Cadiou (likely from C.G.E.) and concerning Etabl. HERVET p. 11.

Ongoing and planned problems (p. 10)

Page 10 lists two "ongoing" subjects: the hydraulically-driven alternator and electro-hydraulic regulation. Then a list of "problems to be undertaken": a "road-holding control and servo-mechanism device" (requiring prior Citroën tests and recordings), a "car speed signal", a "centrifugal force signal" and a "synchronisation signal (e.g. engine - clutch)" p. 10.

Status of work with C.G.E. (p. 11)

Page 11 details, as of 23 February 1961, the progress of the alternators developed in collaboration with C.G.E.:

The footnotes specify the nature of each type: "SRM" = single-phase rotary sector, 2 diodes; "ABT" = three-phase strip magnet, 6 diodes; "ABM" = single-phase strip magnet, 2 diodes p. 11.

Added to this are 400 g and 1000 g electromagnets ("electro"), two of which show "significant friction" p. 11.

Four actions are noted: modification of the C.G.E. hydraulic block (tank and cooling), addition of pipes for regulation tests, study of an electrical vibration by C.G.E., and manufacture of a cast-core alternator p. 11.

Finally, three study tasks are scheduled: the redesign of a hydro-electric regulator, the study of a distribution system compromising between the displacements used, and the improvement of silence p. 11.

Context

C.G.E. (Compagnie Générale d'Électricité) was a large post-war French electrotechnical group, a frequent industrial partner of car manufacturers for electrical components. The development of alternators driven by a hydraulic motor is in line with the logic of the Citroën hydropneumatic system, where hydraulic pressure already powered several of the car's components (suspension, braking, steering). Coupling this hydraulic energy to electricity production would have allowed for the consideration of servo-controlled devices (regulation, speed measurement, centrifugal force) without relying solely on a conventional electric motor.

Archivist's perspective

This document offers a precise and dated snapshot of a research project led by Magès on the sidelines of the suspension itself: it seems that the engineer was exploring, as early as 1961, measurement and servo-control solutions (speed, centrifugal force, engine-clutch synchronisation) that prefigure ideas developed later, as can be sensed in the Notes by Paul Magès on the DS clutch and gear control, written a month later.

The technical precision (alternator types, voltages, displacements) and the mention of several prototypes in progress at C.G.E. and Hervet suggest a project followed with rigour, probably discussed regularly internally, as suggested by the minutes of BBC meetings from the same period, such as the Summary of the BBC meeting of 22 February 1962.