HOT voltage regulators

[skristof]

I just gave the radio it's first try. The app detected the radio and started to record, but I had to shut it down as the voltage regulators were both getting very hot. I noticed it when a piece of nearby insulation starting to smoke.
Any help on a cause and/or cure for hot voltage regulators would be appreciated.

[kckerbypatel]

That doesn't sound right. What are the model numbers on your voltage regulators?

[skristof]

One is 7812 and the other is 7912 as specified in the parts list and instructions.

[kckerbypatel]

Ok, so that's not it. And they're wired right, or you wouldn't have seen anything and/or the regulators themselves would have blown up. (I destroyed one early on because I assumed they had the same connections, and they don't.)

I'll have to think about this - I haven't seen this issue before. Could you post a photo of your setup?

[dlleigh]

Are the two regulators swapped? As K. C. Kerby-Patel mentioned, that could cause them to get hot. His were destroyed, but he may have been running from a bench-top power supply while he was testing.

If you are running off the batteries, it is quite possible that the regulators would just get hot without being destroyed. Batteries, especially 9V, cannot source as much power as a bench supply.

[morristownlib]

I'm in the same boat. I do know I had to wait for some version change stuff to happen and we are were in a group for this project but as Lead person I had been able to take it home last night and sit down and try to test it this evening. Upon verification of all the work and wire placements I put the batteries in and got a heart beat to my Tablet and was able to record something. Within about 1 min mark I could feel heat coming off the regulators. I doubled Checks #'s and Locations... I do understand that this should get warm in some designs but if this is going to cook an egg I would not have built it the same way and used a much larger Breadboard to make sure there was more clearance.


- side L7912
+ side L7812

I had to make one change to the a pair of jumpers to allow for the switch to properly be placed but as with any Bread board I do understand Rows/Columns for Placement so I can pretty much rule out a Misplacement. I was going to change it back and remove switches but before I did I came to the forum and noticed this post.

Even with the heat though it does appear that there was data being captured

[morristownlib]

Having the same issue. Double checked everything and even though there is still several images that do not actually match in color coded wire or one or two steps off I have double check several "final Images" of the build.. The only difference I have is that version 2 kit upgrade with the 270pF Cap my is labelled as 271pF if I understand the conversion one is rated at 100 the other 50..


Could this be the issue?

Wayne

[skristof]

Just ran the receiver again to see if I get a signal from WWVB at night.
Not only do the voltage regulators get very HOT, the batteries get warm also.
If no one else is having this experience, then I clearly have the power supply wired incorrectly or the power supply has one or more bad components.
The app detected the receiver again, but the TEST came out No Signal Detected.

[Kevin Keegan]

Hi skristof,

I had this happen to me several times while I was testing the circuit. There must be an incorrect connection somewhere in your setup. When the receiver is wired correctly the voltage regulators should not heat up like that. I would start looking for a miswired connection around the voltage regulators and go from there.

Can you post a photo of your circuit? We might be able to help spot the issue.

[erk71]

My 7912 gets hot too, but no problems with successful recordings and testing. Batteries stay normal temperature. I suggest you re-check all of your connections, for snugness.