Volt Meter ?

[Bwilly]

I recently purchased a VV Tube mod. When I use the volt meter on it the light just flashes. I tested it on my other mods and it works just fine. Could someone out there tell me what this means. Is it my mod or my volt meter ? Thanks.

 

[Baditude]

The reason your volt meter works on your "other mods" (I'm assuming you mean mechanical single voltage mods) and not on your VV tube mod is the VV mod's boost circuit is putting out pulse width modulation (PWM) current to acheive variable voltage. Your particular volt meter is unable to test this "wave form" of spikes and dips of pulsing output, it can only read or measure a fixed steady current output like a mechanical mod makes.

An osceloscope is necessary to be able to measure the spikes and dips output of PWM. The below video tutorial that describes how PWM can control output voltage of a VV mod and shows the waveforms created by PWM..

 

[Bwilly]

Thanks for answering my question. Happy to know there is nothing wrong with my mod