  Dedicated accelerometers have been developed for the MICROSCOPE mission
taking into account the specific range of acceleration to be measured on board
the satellite. Considering one micro-g and even less as the full range of the
instrument, leads to a customized concept and a high performance electronics
for the sensing and servo-actuations of the accelerometer test-masses. In
addition to a very accurate geometrical sensor core, a high performance
electronics architecture provides the measurement of the weak electrostatic
forces and torques applied to the test-masses. A set of capacitive sensors
delivers the position and the attitude of the test-mass with respect to a very
steady gold coated cage made in silica. The voltages applied on the electrodes
surrounding each test-mass are finely controlled to generate the adequate
electrical field and so the electrostatic pressures on the test-mass. This
field maintains the test-mass motionless with respect to the instrument
structure. Digital control laws are implemented in order to enable instrument
operation flexibility and a weak position sensor noise. These electronics
provide both the scientific data for MICROSCOPE's test of General Relativity
and the data for the satellite drag-free and attitude control system (DFACS).
