Fun with Flybacks: Building a 600V Supply

RE: Fun with Flybacks: Building a 600V Supply

Maxbiggair — Fri, 31 May 2024 08:04:13 GMT

Wow! Very self explanatory.

What about using a PWM instead of astable multivibrator, just to vary the duty cycle

RE: Fun with Flybacks: Building a 600V Supply

shabaz — Wed, 06 Dec 2023 21:45:19 GMT

I felt uncomfortable leaving this blog post with just a poor breadboard layout, and I also wanted to be able to experiment a bit more with the circuit, so a PCB layout is now created (the blog is updated with the info).

The board allows for an external signal source if desired, using a slide switch to select between the 555 and the external source.

RE: Fun with Flybacks: Building a 600V Supply

DAB — Thu, 23 Nov 2023 19:44:40 GMT

Very good blog.

The old color TV sets used a flyback transformer to generate about 25 Kv.

You had to treat those with a lot of respect.

RE: Fun with Flybacks: Building a 600V Supply

jc2048 — Wed, 22 Nov 2023 11:34:58 GMT

Thanks. A fun blog and nicely inspiring. I think I've learnt that I need to go back to some books and see if I can relearn some of the theory of this.

I think that you are right to say your circuit is inefficient due to the lack of a controller - as it stands, the output regulation is done indirectly by the core-reset circuit, and when that comes into play it dissipates a fair proportion of the energy.

Obviously, this is a flyback circuit, uses a flyback transformer, and would get called a flyback converter. But how should one describe the switching topology?

I'd call this a boost switching topology. [Note that boost here isn't referring to what the output of the converter is doing - there I prefer the use of step-up and step-down - it's referring to what's happening at the switching node.] Am I wrong to do that?

RE: Fun with Flybacks: Building a 600V Supply

michaelkellett — Wed, 22 Nov 2023 09:30:11 GMT

Interesting blog.

And what a grim way of gapping a transformer (random sized bits of paper) - any idea where these parts were intended to be used ?

RE: Fun with Flybacks: Building a 600V Supply

javagoza — Wed, 22 Nov 2023 07:56:17 GMT

Thank you very much Shabaz, a very educational blog. I have enjoyed reading it. For a few years I worked in an Apple repair shop in the summer. I remember how we discharged the CRTs of the Macintoshes by grounding the CRT anode that was connected to the flyback transformer in order to remove the PCB. Sparks could be seen when touching the ground with the screwdriver, really dangerous.

RE: Fun with Flybacks: Building a 600V Supply

Andrew J — Wed, 22 Nov 2023 07:12:25 GMT

I liked this - really informative experiment. I wouldn't go near it of course, 600V is a bit tasty for me.

When I was at Polytechnic, an old CRT was thrown out and a few of us sneaked it back in with a wild view of fixing it - the Porter was adamant it should stay in the rubbish pile where it belonged. Fortunately we were way too lazy (and didn't really bother with watching TV much) to do anything as our total sum of electronics knowledge floated around nothing.

RE: Fun with Flybacks: Building a 600V Supply

robogary — Wed, 22 Nov 2023 02:01:23 GMT

very cool and I learned a thing or two. Thanks

RE: Fun with Flybacks: Building a 600V Supply

genebren — Tue, 21 Nov 2023 23:41:24 GMT

Excellent blog on your flyback transformer experiments! I don't know if I would have the desire or guts to attempt to experiment with 600V in my workspace, but hats off to you for trying it out. Well done!