19-01-2018, 10:41 AM
I remember seeing an ingenious design somewhere for a bench AC PSU which could provide any output from 1V to 40VAC in 1V steps that used this technique.
A small number of secondary windings were used either singly or in combination to give the desired result by using in and anti-phase connections.
The windings - I think I've got this right! - were 1V, 3V, 9V & 27V.
These were combined as follows:
1 = 1
2 = 3 - 1
3= 3
4 = 3 + 1
5 = 9 - 3 - 1
6 = 9 - 3
7 = 9 - 3 + 1
8 = 9 - 1
9 = 9
10= 9 + 1
11= 9 + 3 - 1
12= 9 + 3
13= 9 + 3 + 1
14= 27 - 9 -3 - 1
and so on up to:
40= 27 + 9 + 3 + 1
Clever, huh?
A small number of secondary windings were used either singly or in combination to give the desired result by using in and anti-phase connections.
The windings - I think I've got this right! - were 1V, 3V, 9V & 27V.
These were combined as follows:
1 = 1
2 = 3 - 1
3= 3
4 = 3 + 1
5 = 9 - 3 - 1
6 = 9 - 3
7 = 9 - 3 + 1
8 = 9 - 1
9 = 9
10= 9 + 1
11= 9 + 3 - 1
12= 9 + 3
13= 9 + 3 + 1
14= 27 - 9 -3 - 1
and so on up to:
40= 27 + 9 + 3 + 1
Clever, huh?
