NOON
Well-known member
I have to build a power supply for a Neumann KM56, 120V at ~1mA and 4V at ~100mA.
First thoughts are bog standard suitable TX, rectifiers, filters, TL783 for the 120V and LM317 for the 4V with trimpots for fine adjustment. But second thoughts are 'can this be improved?'
Any ideas on whether it's worth going to more effort/expense for this power supply?
Any ideas for fancy features? One idea that came to mind is a delay circuit for the high voltage that detects current on the filament rail and then switches a relay on after about 30 seconds. Gives the valve some time to warm up before HT hits and keeps the HT safely isolated from the outside world when nothing is connected.
First thoughts are bog standard suitable TX, rectifiers, filters, TL783 for the 120V and LM317 for the 4V with trimpots for fine adjustment. But second thoughts are 'can this be improved?'
Any ideas on whether it's worth going to more effort/expense for this power supply?
Any ideas for fancy features? One idea that came to mind is a delay circuit for the high voltage that detects current on the filament rail and then switches a relay on after about 30 seconds. Gives the valve some time to warm up before HT hits and keeps the HT safely isolated from the outside world when nothing is connected.