Patent ID: 8203908

Claim:
A method for causing the generation of a mud pulse by a controlled pulser's main pulse valve comprising: powering movement of a servo-poppet within a servo-valve in a first direction away from a servo-orifice within the servo-valve using a rotary motor via a connected rotary-to-linear transmission, such that mud is permitted to flow past the servo-orifice to activate a main mud pulse valve; powering the movement of the servo-poppet in a second direction toward the servo-orifice using the rotary motor and transmission such that the mud-flow past the servo-orifice is restricted to deactivate the main mud pulse valve; and using the motor, when unpowered, as a brake against a rotational force exerted on the motor from pressure of mud-flow on the servo-poppet at a restricted position of the servo-valve, wherein the motor acts as a brake by shorting coils of the motor together.