Abstract: An operating well such as an oil well is provided with a safety valve in the tubing thereof. A control cartridge controls the safety valve under the command of control signals transmitted from the surface. The control cartridge includes a housing mounted in the tubing and a receiver for receiving signals transmitted from the surface. A power supply is provided in the housing and is connected to an electronic control system, which control system is also connected to the receiver. A hydraulically operated actuator controls the safety valve, and a source of hydraulic fluid is provided in the housing and connected with the hydraulically operated actuator for operating the actuator. The source of hydraulic fluid is also connected to the power supply for operation thereof.

Abstract: An electronic device comprises an arrangement which makes it possible to power a transmitter in self-contained fashion from a pick-up without any other power source. The device comprises at least one transistor and a transformer having a high turns ratio. The primary windings are connected in series with controlled electrodes of the transistor. The secondary windings of the transformer act on the controlling electrode of the transistor and the very low voltage is applied across the primary windings and the controlled electrodes. Voltages of a few mV which are thus applied result in the appearance of voltage pulses of a usable magnitude at the terminals of the secondary winding which may be accumulated in a capacitor to feed the transmitter intermittently. This device can be used in a self-contained detector-transmitter for use as a remote fire alarm.

Abstract: The present invention has as an object the provision of an electromechanical analogic display device for electronic chronometers, comprising at least an electromagnetic motor controlled by an electrical impulse of short duration. The attractive influence of the latter distorts a spring, very rapidly storing the produced energy to release it in the form of kinetic energy and driving a toothed wheel coupled to the analogic display while on the other hand this electromagnetic motor activates a locking system permitting the passage of a single tooth per cycle, and thus assures for said device immunity from mechanical shocks and most particularly from tangential accelerations.