Broken Breadboard Power Supply

Other Hardware General Electronics
1

Bought one of these on ebay: http://compare.ebay.com/like/271215867354?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

I can't get the 5v output to work correctly. The 3.3v works fine on both sides, but when I switch to 5v, it just passes through whatever the input voltage is.

I thought maybe I had exceeded the voltage limits of the 5v voltage regulator, but i've switched out the 5v smd regulator and tried using lower voltage sources. Either way, the 3.3v works fine no matter what I throw at it.

Any ideas?

2

What are you using as an input voltage?

3

12v wall wart, which ended up being somewhere around 18v. I tried running that through a 12v regulator first and I also tried a 9v.

Now that I'm thinking about it, maybe I blew it with the 18v, swapped it and then did it again?

If so, how could the 3.3v be so much more tolerant?

4

You're probably right. 18v = "magic smoke". :cold_sweat:

You could try looking up part numbers on regulators & viewing the DATASHEETS. Perhaps one of them is more tolerant of higher voltages?

Let us know if you find out!
Thanks.