This circuit is from a time when this type of feature was not common in line cars. The pulse transformer has a 1: 1 turn ratio and the SCR admits equivalents.
This circuit cut the noise peaks by means of diodes so that they do not appear in the output...
This trigger circuit was found in an American documentation from the 1980s. The amplifiers used...
We found this circuit in a 1995 paper. The reed switches are surrounded by a few coils of coarse...