Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

RE: final report on switching trans vs halo trans for filament supply

Posted by Triode_Kingdom on January 3, 2017 at 09:27:43:
Glad to hear it's working for you.

"Now all I have to do is try and get one of the 60 watt halo units down to 1.5 volts ac and give that a try on the 26's."

After more work on this, I don't think these high step-down ratios will be feasible with the half-bridge circuit. It might be better to gut the oscillator components (except the two switching transistors) and add a daughter board. The added board could use a high speed, differential output device to drive the two transistors. With this approach, frequency could be set using RC components, and the duty-cycle could be adjusted to exactly 50% for ease in setting the RMS voltage. This might also have some benefit in generating the higher filament voltages needed for 211/845/GM70 tubes. I'll post any progress I make with this.