摘要:
The invention relates to a voltage conversion method specially feasible for the transformation of low voltages to high voltages by means of a switching convertor. The method according to the present invention eliminates the current transients (B) through the switching unit (S), which is controlled in such a way that the time period (t.sub.F) during which the switching unit (S) is in its off-state is made to have a duration such that the resonance voltage (D.sub.u) on the transformer windings always has a predetermined phase, when said switching unit (S) is triggered to change to its conduction state. Voltage conversion according to the invention has high efficiency and causes little radio-frequency interference.
摘要:
A phase monitor for a short-circuited asynchronous three-phase motor comprises a first and a second sensing unit, both of which are connected to a supply voltage line to the motor in order to sense the voltage conditions on the line, and a control switch which is controlled by the two sensing units and connected in a control circuit for a supply voltage switch for the motor, connected in the supply voltage line. When the supply voltage line is connected to a supply voltage source, the first sensing unit causes an immediate switching-on operation of the control circuit if the voltage conditions on the supply voltage line sensed by the first sensing unit at that moment are acceptable. After a switching-on operation of the control switch caused by the first sensing unit, the second sensing unit, which is operatively connected to the control switch via a delay unit, provides a delayed control of the state of the control switch in dependence upon the voltage conditions on the supply voltage line sensed by the second sensing unit.
摘要:
A coaxial high repetition rate pulsed gas laser is provided, having a peak value pulse to pulse reproducibility better than 1% at a repetition rate of up to 400 Hz. This is accomplished by synchronizing the time evolution of the high tension laser electrode voltage with the gas break-down delay period in such a way that the laser output and stability are optimized.