Ckd Praha, Oborovy Podnik

Ceskoslovenska Akademie Ved

Richard Jelinek

Jan Krtek

Josef Cibulka

Jiri Winkler

Jaroslav Hlousek

Milan Kondr

Vladimir Mlynar

Josef Simacek

Miroslav Peterka

Zdenek Rychter

Jan Bryksi

Vladimir Mickal

Inverted current rectifier with self commutation for smaller and medium output and three-stage commutation in which the disconnection of thyristors of the inverted rectifier and the current commutation in the phases are separated and the accumulated power of capacitors of the inverted rectifier is, without losses, discharged to the current source and thus to the load of the inverted rectifier.

Circuit arrangement of an inverted current rectifier with self

Circuit arrangement for inverters with three stage self-commutation suitable for large outputs and for parallel connection of main thyristors and separating reactors.

Circuit arrangement for self-commutated inverters

Method for testing of the embryotoxicity in the chicken embryo consists in reading the response of caudal morphogenetic system (CMS) of a chicken embryo to the presence of the tested substance in subgerminal fluid. The function of the caudal morphogenetic system is evaluated 24 hours after application by a simple quantitative parameter -- the length of a newly-formed part of the trunk. The substance, which interferes with some of the basic morphogenetic processes, slows down, stops or modifies the formation of the shape of the caudal part of trunk. Considering that the quantitative parameter is used as the index of the CMS function, each member of the experimental set presents information, not only the dead and malformed embryos as in classical methods. The second part of the test, i.e. the more precise determination of the beginning of the direct embryotoxicity range, serves above all for disclosure of the effect of the tested substance on the circulation system of the embryo and smooth muscles of faetal membranes. The testing according to this method may be used in pharmaceutical productions and plants, further in chemical productions and for environmental monitoring.

Method for testing of embryotoxicity on chicken embryo

A test circuit for determining when one of a number of source voltages deviates from its set point. Each source voltage has coordinated comparison circuit which compares the voltage with a preset value, and which has a limited range of output voltage. Each comparison circuit has its output connected to a switching circuit. The output of each switching circuit is connected to a short circuit coil of one coupling transformer. The coupling transformer is fed from an auxiliary current source through an auxiliary coil and has as output a pick-up coil connected to an evaluation device.

Test circuit for indication of deviation of source voltages from their

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Richard Jelinek