[dayneger]

Hi everyone!

I've been enjoying listening to my 100W AKSA, wonderful amp.

I still have problems with the surge when I turn it  on, though, and my Swiss landlord isn't particularly psyched about putting in a slower-trip circuit breaker for my audio pleasure.  Weird.

So, I'm looking for other ideas.  One possibility is this little project here:  http://sound.westhost.com/project39.htm

Anyone have other ideas or implementations I could consider?

Thanks in advance!

Dayne

[AKSA]

Dayne,

The switch-on surge comes from the toroids, which draw about ten times full rated current for a couple of cycles at actuation.

The best option is a Varistor  in series with the active lead to the transformers.  This senses high current, radically raises its resistance, then when the current settles down, drops its resistance to negligible levels.  Widely used in pro-audio.

Look 'em up on google;  finding them might be difficult in Zurich, but they are widely available.

Cheers,

Hugh

[dayneger]

Hi Hugh,

Thanks for the tip.  I don't think I've found the right thing yet here--most of the applications I came across referred to the varistors primarily for blocking voltage spikes, not for limiting current surges.

Could you tell me approximately what the specifications should be for this situation?  That would definitely help me find the right thing.

Thanks!

Dayne

[bsy]

Hi

I think it should be thermister instead of varistors.
thanks

[bsy]

Hi

I would like to add a NTC Thermistors in the active lead prior to the power transformer on my AKSA 100W for the purpose of the surge protection Can anyone suggest how to determine the right spec for this NTC

http://www.thermometrics.com/assets/images/cl.pdf