Abstract.One of the most important diagnostic parameters of an oil well operation is the dynamic liquid level in the annular space. In paper the main methods for determination of the dynamic liquid level that does not require suspension of the well work and its depressurization are considered. Also the comparative analysis of these methods is given.

The principle of building fault-tolerant digital control systems for power supplies of space vehicles is considered in the article. The analysis of the circuits by sampling the controlled component of the output voltage at discrete instants of time is carried out. The possibility of using this approach in multi-channel digital control systems is shown. The results of theoretical studies are confirmed by the example of a four-channel control unit.