Voltage regulator arrangement for preventing overvoltages

Claim 1

Voltage regulator arrangement for regulating the load voltage across a direct current load, comprising, in combination, alternating current generating means having a first output winding, and a second output winding magnetically coupled to said first output winding; rectifier means interconnecting said first and second output windings and said direct current load; first and second switching means, having a first and second control electrode respectively and adapted to have a unidirectional conducting state in response to control signals applied to said control electrodes; means connecting said first switching means across said first output winding; means connecting said switching means across said second output winding in such a manner that a substantially continuous short circuit exists across said magnetically coupled output windings in response to control signals at said first and second control electrodes; and control circuit means connected between said direct current load and said control electrodes, said control circuit means comprising: a control circuit Output terminal; control switching transistor means having an emitter-collector circuit interconnected between one side of said direct current load and said control circuit output terminal for changing the voltage at said control circuit output terminal from a first to a second level when said load voltage exceeds a predetermined voltage; interconnecting means interconnecting said control circuit output terminal and said first and second control electrode in such a manner that said second level constitutes said first and second control signals; and an additional control element having a predetermined voltage breakdown characteristic connected in parallel with said emittercollector circuit of said control switching transistor.