Re: Ballast for low pressure mercury lamp



Good call, thanks for your help. All four of the bridge diodes have 0 Ohms of resistance both ways. I have another ballast that blew a fuse but the diodes appear to be okay on that one.



I couldn't find these after searching for a while. I guess the circuit in the patent is not exactly the same.

A few more things I found:[list][*]The circuit appears to be some type of flyback converter. The circuit seems very simple compared to other real world switchers.[*]There is no in-rush...

Re: Ballast for low pressure mercury lamp



Yup, that's it. Thanks....

Sorry for the offtopic post but I hope someone here has some advice. My parents live on a farm and use a UV sterilizer for their water. The ballast on the low pressure mecury UV lamp keeps blowing caps and fuses. I'm wondering if it's due to bad power, bad components or just bad design.

A little searching reveals the following patent: US 6274988 (. The circuits in the patent appear to match the board I have. The half-bridge driver is a International Rectifier IR2151. The two MOSETs are IRF830. The big electrolytic caps (47 uF, C1 & C2 on page 3 of the patent) don't seem to have...