Deepdark
Well-known member
Hi
I got a question for you guys. I'm looking to build a AM864 and I was looking at the psu and started interogating myself about the heaters winding (both for the rectifier and the tubes).
When looking at, for exemple, Hammond / Allied transformer, some have a 6.3V coil and 5V coil too. Some are center taped and some not. Sometime, the 6.3v coil is cente taped but not the 5v coil. Then I looked at the XPWR012 from Edcor.
This one has a 6.3V coil that is center taped, so basically 3.15V-0V-3.15V. Which means that betwen one of the lead and the center tap, we have 3.15V, same with the other end, so we have a total of 6.3V between both ends when center tap is connected to ground. Isn't it?. Does that mean each wire carries 3.15V? I mean, if I run them to a tube and connect to pin 4-5 and 9 so we're in paralelle and should read 6.3V between pin 4-5/9, meaning that each pins is fed by 3.15V? If I run them to pin 4 and 5, so I need to provide 12.6V, so we're better off with a 12V filament coil? What happened with a non center taped coil? we have 3.15v at both end, too, or only one wire run all 6.3V and the other lead is our common, like the primary side (for exemple 120V-common)? We need to make an artificial tap to ground at each end to help shunt leakage from the primary, isn't it?
Now, looking at the 5v coil of the XPWR012, it has no center tap and it indicate 5V at one end and common at the other end. Does that mean it is not balanced? I doupt it's what we need to feed the 5Y3 filament pin 2 and 8 isn't it? This one struggle me a little loool.
Sorry if that seems to be a nooby question. I like to understand the maths behind everything I did, not simply painting by number
I got a question for you guys. I'm looking to build a AM864 and I was looking at the psu and started interogating myself about the heaters winding (both for the rectifier and the tubes).
When looking at, for exemple, Hammond / Allied transformer, some have a 6.3V coil and 5V coil too. Some are center taped and some not. Sometime, the 6.3v coil is cente taped but not the 5v coil. Then I looked at the XPWR012 from Edcor.
This one has a 6.3V coil that is center taped, so basically 3.15V-0V-3.15V. Which means that betwen one of the lead and the center tap, we have 3.15V, same with the other end, so we have a total of 6.3V between both ends when center tap is connected to ground. Isn't it?. Does that mean each wire carries 3.15V? I mean, if I run them to a tube and connect to pin 4-5 and 9 so we're in paralelle and should read 6.3V between pin 4-5/9, meaning that each pins is fed by 3.15V? If I run them to pin 4 and 5, so I need to provide 12.6V, so we're better off with a 12V filament coil? What happened with a non center taped coil? we have 3.15v at both end, too, or only one wire run all 6.3V and the other lead is our common, like the primary side (for exemple 120V-common)? We need to make an artificial tap to ground at each end to help shunt leakage from the primary, isn't it?
Now, looking at the 5v coil of the XPWR012, it has no center tap and it indicate 5V at one end and common at the other end. Does that mean it is not balanced? I doupt it's what we need to feed the 5Y3 filament pin 2 and 8 isn't it? This one struggle me a little loool.
Sorry if that seems to be a nooby question. I like to understand the maths behind everything I did, not simply painting by number