DIY DC blocker?

[Reid Malenfant]

Dave, why did you reverse both the diodes & capacitors? It's wrong...

Go back to the diagram you had previously & simply reverse both capacitors

[HighFidelityGuy]

Dave, why did you reverse both the diodes & capacitors? It's wrong...

Go back to the diagram you had previously & simply reverse both capacitors

Doh , I'm with you now. Cheers.

[Reid Malenfant]

That's the way to do it

PM me your AD & i'll send you one of the MUR3040PT, I know where they are so it's not like i have to go hunting them down

By the way, depending on what you are going to power you'll need to take into account the current carrying capacity of the capacitors, check out there ripple current rating.

[colinB]

Mark,i thinks its time you started designing and making some products.

[Reid Malenfant]

Making my own stuff is as far as i'm willing to go Colin I don't mind helping out like this & i can't stand stuff that's wrong, god knows what that bloke was thinking when he posted that circuit on the net

Oh sorry, what am i on about? He wasn't thinking

[HighFidelityGuy]

Here's another DC blocker schematic I've just found:



What do you think about that one Mark? Would this be any better or worse?

[Reid Malenfant]

Why bother making something more complicated than it needs to be? It'll be more expensive & work no better than the two diode two capacitor version

Besides which the diodes are back to front yet again!

[HighFidelityGuy]

Ok thanks Mark.
I can see that if you chop the right hand side of that last circuit off you're left with the circuit you recommended.

It's quite scary that both of the first to circuit's I posted are wrong and they've been in circulation for several years with many people making and using them. No wonder quite a lot of them said they didn't notice much difference in transformer buzz after installing it.

Google can be a dangerous tool at times. I'm glad I asked before I jumped in.

Cheers.

[Reid Malenfant]

They will probably work, in fact they will work with the diodes back to front as long as little DC voltage is present on the line. However with the diodes wrongly orientated the capacitors have zero protection against DC reverse voltages greater than 0.7V. What this means is that if there is significant DC on the line then the capacitors could well blow up

[HighFidelityGuy]

Nice.

I'll drop you a PM in a minute about the diode. Thanks for the offer btw.
On the subject of caps, I have a few of THESE left over from my valve amp build, would they be chunky enough? Cheers.