What did you no understand and what sort of protection do you need? What do you want to protect the speaker against?space2000 said:hi Nordic, thank you for your help. i am not good in electronics. its looks like not comlete circuit. i really didn't understand this web. thank you again for your help.
space2000 said:upc1237 not available in here. thank you.
I built a drop in output relay board for Phase Linear 400's using the UPC1237. I love this chip. So easy to work with. They only work up to 60VDC. The Phase Linear rails run at about 75VDC so I used a 25volt 5watt zener leaving me with a 50 Volt power supply. I'm using a 48VDC relay and the zener doesn't even get warm.
I nearly panicked when I started having trouble finding the chips. Then I found them at Futurlec and ordered 20 as I thought they were suspect. Futurlec site It took about 2 weeks for them to get here. In the mean time MCM got a shipment in and I bought all 50 they had. I haven't tried the ones from Futurlec yet, but I assume they'll work.