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Dropping B+ problem!

2/10/2000 12:02 PM
lion	Dropping B+ problem! I tried to wire up the B+ dropping trick from Randall Aikens site – the one with a power transistor and a low watt zener between the PT CT and ground. I used a 30V zener – but instead of a 30V drop the voltage increased from 430V to 475V - maybe more!!! I shut it down quickly when I saw the voltage go up. Given the simplicity, I’m allmost positive I had it wired up right – (writting this I realize that I could have done some measurings - maybe on the 2N3055 – that could have been helpfull trying to pinpoint the problem/my mistake!) – but I ripped it out, being afraid to exceed max ratings of my filter cap ect. So, before I give it another try – what do you think! Any thoughts will be appriciated Regards Lion

2/10/2000 12:02 PM

lion

Dropping B+ problem!

I tried to wire up the B+ dropping trick from Randall Aikens site – the one with a power transistor and a low watt zener between the PT CT and ground.

I used a 30V zener – but instead of a 30V drop the voltage increased from 430V to 475V - maybe more!!! I shut it down quickly when I saw the voltage go up.

Given the simplicity, I’m allmost positive I had it wired up right – (writting this I realize that I could have done some measurings - maybe on the 2N3055 – that could have been helpfull trying to pinpoint the problem/my mistake!) – but I ripped it out, being afraid to exceed max ratings of my filter cap ect.

So, before I give it another try – what do you think!
Any thoughts will be appriciated

Regards
Lion

Replies:

Ken Gilbert lion, are you telling me you got MO... -- 2/10/2000 5:04 PM
Tracy LionI used this B+ dropping... -- 2/11/2000 7:10 AM