U47 with EF14 tube Build

[rock soderstrom]

hopefully this is better?

looks good. Try it and adjust it if needed

 

[rock soderstrom]

Does C7 do anything, with both terminals grounded?

https://en.wikipedia.org/wiki/Rectifier#Voltage-multiplying_rectifiers

I do not know, I just copied the textbook delon bridge circuit.

https://en.wikipedia.org/wiki/Voltage_doubler

 

[Spencerleehorton]

That’s what I thought was strange as if I don’t gnd the voltage supply it doesn’t run any voltage?
The other option is to take the second gnd out is it?

 

[Khron]

I do not know, I just copied the textbook delon bridge circuit.

Rock, you did; Spence didn't.

https://en.wikipedia.org/wiki/Voltage_doubler#/media/File:Bridge_voltage_doubler.svg

That’s what I thought was strange as if I don’t gnd the voltage supply it doesn’t run any voltage?
The other option is to take the second gnd out is it?

I promise i don't mean to be mean, but... Are you completely sure you should be messing around with things like this, without a (more) comprehensive understanding of the basics?

Sounds to me like there are some confusions and/or false assumptions messing with things somewhere...

https://sound-au.com/articles/index.htm#psud

 

[rock soderstrom]

Rock, you did; Spence didn't.

Now, I see your point. You are right!

 

[Spencerleehorton]

In my defense it didn’t work when I did it correctly that’s why I put the other gnd on there and the sim worked.
And that is exactly why im simulating it before I do it for real

 

[Khron]

In my defense it didn’t work when I did it correctly that’s why I put the other gnd on there and the sim worked.
And that is exactly why im simulating it before I do it for real

So the simulation didn't work if the negative end of V2 was not connected to ground?

 

[Spencerleehorton]

this is the simulation without the gnd on the negative ac side


you can see that all the voltages are off on the H+

 

[Khron]

Sidenote: in LTspice, the amplitude for the sine source is actually the PEAK amplitude, not the RMS value transformer ratings are in. So V2 is putting out 17Vpk, or 34Vpp.

Do you have a particular simulation model for those polarized electrolytic capacitor symbols there? I use the stock symbol you get when you press C on the keyboard, or click the capacitor symbol in the toolbar. I'm starting to wonder if those are actually working as the capacitors they're intended to be, within the simulation...

Just slapped together this quick sim, and works fine with the floating voltage source.

So the heater winding of your transformer is supposed to put out 6.3V AC? That would translate to an 8.8V amplitude for the LTspice sine source. And didn't the UK run on 50Hz mains?

Later edit: 2nd attached screenshot also contains an LM317 with some eyeballed adjustment resistors, putting out about 6.5V (blue trace; white trace is LM317 input voltage).

No idea what exactly is or isn't going on in your sim... Do you have 17V set also as a DC offset for V2? Labels are overlapping with the 1N4007 of D7...

 

[Spencerleehorton]

well i dont know whats going on with my ltspice, as ive put in what you've done and when i check voltages i can see on the plot what the voltages are but when i place data label on there its just a 0v?
on my version of what you have done with the lm317 mine outputs 3v and not 6.5v like yours but all the components are the same?

 

[Spencerleehorton]

ive installed the latest version and it does seem to be almost working, just the data label is incorrect now
when i plot i can see voltages are correct and are what they should be.
just dont know why data label isnt working?

 

[Khron]

on my version of what you have done with the lm317 mine outputs 3v and not 6.5v like yours but all the components are the same?

Screenshot?

just dont know why data label isnt working?

No idea, never used those.

https://electronics.stackexchange.c...ow-can-i-display-the-current-in-the-schematic
Osx seems to be a headache for technical things..(?)

 

[Spencerleehorton]

here you can see the plot which is same as yours but the data label reading 0v?

 

[Khron]

What's in the simulation syntax? Could it be that it defaults to the ".startup" argument being on, and the labels show that initial 0V value?

Still some answers missing though...

So the heater winding of your transformer is supposed to put out 6.3V AC? That would translate to an 8.8V amplitude for the LTspice sine source. And didn't the UK run on 50Hz mains?

No idea what exactly is or isn't going on in your sim... Do you have 17V set also as a DC offset for V2? Labels are overlapping with the 1N4007 of D7...

 

[Spencerleehorton]

if i then change the volatge source to DC and put in 8.8v the 0v labels change to these numbers?

 

[Spencerleehorton]

yes uk on 50hz and yes to 8.8v amplitude on H+ 6.3 x 1.4 = 8.8

i had it set to 17v dv as the sine didnt seem to be working, as this mac version seems to have many problems which are not all my errors

 

[Spencerleehorton]

i can only get what looks like correct data labels when i add the gnd to the negative voltage?
and i have to add 6.3v to dc offset and 8.8 to amplitude and 50hz

 

[Khron]

That Mac version of LTspice does indeed seem to be all over the place, for reasons i can't even speculate on...

If you add a DC offset to that, how do you expect that (AC-coupled) voltage doubler to do what it's supposed to do? No point in bothering simulating that voltage doubler arrangement at all, in the first place, then.

 

[Spencerleehorton]

i think i know whats going on, the data at 0ms is being shown rather than at 100ms to where im measuring? how to i correct that?
but it still doesnt correct the dc offset?

 

[Khron]

What "dc offset"?

And CAN you even display anything else than the results of the .op (DC quiescent operating point), in those labels?