29-07-2015, 05:06 PM
(This post was last modified: 29-07-2015, 05:09 PM by Radio Fixer.)
Well, having bagged things quickly and then wished I hadn't (there will always be another) I wouldn't. It doesn't say and I don't want to get drawn into too deep a study so I may have missed it, that the 220V output is a completely separate wdg (winding) and you would want that. And you don't need 100VA ... think how much a valve takes ! How big is the thing and is it over specified anyway (probably!).
As to the other piece of electronics it waxes lyrical about over current but being variable it doesn't say anything about over voltage. So there you are with a rare valve with a 1.5V heater and it suddenly loses control, nice light bulb for a few moments.
With a transformer, of some sort, and separate voltages its simple with little to go wrong, apart from selecting the wrong tap. As to setting a repeatable voltage than a Variac on the input will do that for you and be a useful piece of kit for other applications. AVO did it of course by having a mains Xformer with selectable input tapings with a switch. In conjunction with the meter. If you haven't seen one of these try to get someone to show you a MK1 or MK 2 (the only ones I know).
Gary
As to the other piece of electronics it waxes lyrical about over current but being variable it doesn't say anything about over voltage. So there you are with a rare valve with a 1.5V heater and it suddenly loses control, nice light bulb for a few moments.
With a transformer, of some sort, and separate voltages its simple with little to go wrong, apart from selecting the wrong tap. As to setting a repeatable voltage than a Variac on the input will do that for you and be a useful piece of kit for other applications. AVO did it of course by having a mains Xformer with selectable input tapings with a switch. In conjunction with the meter. If you haven't seen one of these try to get someone to show you a MK1 or MK 2 (the only ones I know).
Gary
