The inverter I had a look at some time ago looks like it dates from 1967 from the date codes on the transistors and has some degree of regulation provided by the negative HT connection being made via the biasing circuit for the transistors. The unmarked resistor is 3.6 ohms. The writing looks a bit rough on the 150 ohm resistor too.
It is a very rough reverse engineering diagram I am afraid. All the windings are on a single core but it is not clear in the diagram.
The secondary of the transformer is sadly open circuit and I did an experiment to see if all the lams can be extracted from the transformer and got all but one or two out intact.
The transformer winder needs the top bearing finished off and then I will fix the transformer and start a new thread.
It is a very rough reverse engineering diagram I am afraid. All the windings are on a single core but it is not clear in the diagram.
The secondary of the transformer is sadly open circuit and I did an experiment to see if all the lams can be extracted from the transformer and got all but one or two out intact.
The transformer winder needs the top bearing finished off and then I will fix the transformer and start a new thread.
