10-07-2018, 10:53 AM
(This post was last modified: 10-07-2018, 10:54 AM by pamphonica.)
Just a small suggestion, as half turns are definitely not available on toroids.
Could you add a small winding to put in series with the primary? That would slightly lower the output voltage, and thereby allow you to use exactly 9+9 turns for your heaters. You could adjust this simple additive winding a lot more easily than the centre-tapped low-turns secondary.
I've used this often in the past to modify output voltages on HT transformers where they are a bit too high or low. Add (or subtract) an unused heater winding to the primary and it can work nicely.
Jeremy
Could you add a small winding to put in series with the primary? That would slightly lower the output voltage, and thereby allow you to use exactly 9+9 turns for your heaters. You could adjust this simple additive winding a lot more easily than the centre-tapped low-turns secondary.
I've used this often in the past to modify output voltages on HT transformers where they are a bit too high or low. Add (or subtract) an unused heater winding to the primary and it can work nicely.
Jeremy
Jeremy. G8MLK. BVWS Chairman. British Vintage Wireless and TV Museum Friend.
Pamphonic Website ______________ BTTT OB Truck Restoration
Pamphonic Website ______________ BTTT OB Truck Restoration
