Greetings. I'm building a power supply, using the book "TAB Electronics Guide to Understanding Electricity and Electronics" by G. Randy Slone. Feel free to check my earlier posts on this if you want to know more.
I'm moving along here... have now installed the bridge rectifier, which went without a hitch, and the filter caps.
According to the book, after I've installed the caps, I should get a reading of around 34v DC across them. All good there...checks out great.
Then, it says to measure AC Volts across them to check the ripple, and I should get a reading of 5-20mV. When I check AC volts across them, I get a repeatedly changing value... seems to be oscillating, over a wide range.
The book calls for me to use two 4400uF caps. I didn't have that, but I did have four 2200uF ones, so I wired them in parallel. I've double checked all the connections (after discharging the caps of course) and everything seems to check out ok.
I noticed the behavior happens after the power has been turned off from the supply as well and the caps are charged.
Is this a common error or a red flag to something specific?
I may just go and get 2 4400uF caps anyway to make it more neat inside. Admittedly squishing all those caps in there makes it difficult to work on... made me glad I got my chops up for working in tight places from that classic old board game, "Operation" as a kid... haha.
ahem.
Thanks!
I'm moving along here... have now installed the bridge rectifier, which went without a hitch, and the filter caps.
According to the book, after I've installed the caps, I should get a reading of around 34v DC across them. All good there...checks out great.
Then, it says to measure AC Volts across them to check the ripple, and I should get a reading of 5-20mV. When I check AC volts across them, I get a repeatedly changing value... seems to be oscillating, over a wide range.
The book calls for me to use two 4400uF caps. I didn't have that, but I did have four 2200uF ones, so I wired them in parallel. I've double checked all the connections (after discharging the caps of course) and everything seems to check out ok.
I noticed the behavior happens after the power has been turned off from the supply as well and the caps are charged.
Is this a common error or a red flag to something specific?
I may just go and get 2 4400uF caps anyway to make it more neat inside. Admittedly squishing all those caps in there makes it difficult to work on... made me glad I got my chops up for working in tight places from that classic old board game, "Operation" as a kid... haha.
ahem.
Thanks!
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