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View Full Version : WTD - Mains traffo for SE amp project, 200 to 250V sec plus heater secs


Firebottle
06-02-2017, 16:37
Now sorted.

Search your old stock you valve kit hoarders please :)

I need something to replicate this spec, or not too far away as I can tweak things:

240V primary
200V ish 0.18A secondary, more voltage isn't too much of a problem.
6.3V heater secondary, at least 2A
5V heater secondary, at least 2A.

Can accept twin 6.3V heater secondaries, or 3.15-0-3.15V as I can use alternative rectifiers.
Arkless Electronics
06-02-2017, 17:47
Hmm... low impedance output valve(s).... Interesting ;)
Firebottle
06-02-2017, 17:55
Maybe jumping to conclusions there my mate, I've got a gash incomplete kit, but it does have output transformers with it :)
Arkless Electronics
06-02-2017, 18:00
Maybe jumping to conclusions there my mate, I've got a gash incomplete kit, but it does have output transformers with it :)

Ah well i'm sure you can see why it was a reasonable conclusion from the spec of the mains TX... Carry on :)
Bigman80
06-02-2017, 18:07
Is this to do with the tube buffer ? Lol

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Firebottle
06-02-2017, 19:14
No Oliver , different project. Have just identified a small mains trannie for the buffer.
JohnJo
07-02-2017, 10:14
Could you just run the HT straight off the mains and buy a transformer solely for the heater supplies?

Are there any advantages of running through a transformer, block DC maybe? :scratch:
Firebottle
07-02-2017, 13:56
Safety.
There are designs, particularly from 120V supplies that use the direct mains but this is very risky, particularly if the Line and Neutral are swapped over anywhere.

Do NOT try this at home folks.
Bigman80
07-02-2017, 16:20
No Oliver , different project. Have just identified a small mains trannie for the buffer.
Sweet

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disarmamant
07-02-2017, 16:23
Safety.
There are designs, particularly from 120V supplies that use the direct mains but this is very risky, particularly if the Line and Neutral are swapped over anywhere.

Do NOT try this at home folks.

Quite, but it did not stop Linn Products from doing it with thier valhalla power supply on the LP12.... :eek:
Firebottle
07-02-2017, 18:53
OK, I'm sorted now, just ordered a 100VA trannie and will use another for the main heaters that I have in the gash 'stock'.