PSA: Situational Awareness!!!
Good afternoon, fellow eevBloggers... today I'd like to take a moment to talk with you about Situational Awareness.Above we can see a first-person view all of you should be pretty familiar with. I was having a little "quiet time" troubleshooting an old linear power supply. Had my datasheets printed out, several reference schematics all around me... I was just pleased as a mouse in a barn with an open grainery. Well, after a while I'm pretty convinced the LM723 has given up the ghost again; this thing had poor OCP on its best day, as the series-pass driver can spike 5A base current up the chain. I'm sure it hasn't gotten any better in the last 30 years with dried-out caps and the death of the 2N3055s it was designed with. But hey... I have one in a junk PCB I can scavenge, so it's all good, right?
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/xgrin.gif.pagespeed.ic.QVVz6XIT20.png)
Anyways... all this while, I had been experiencing a gradual warming in my nether regions... like the proverbial frog in a slowly warmed pot of water, I didn't notice anything until it was much too late; in fact I probably would've found the sensation pleasant at first, had I actually taken note.
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
But hey; who among us hasn't gotten a little tingly when puttering away at the bench, especially at that
Eureka! moment, right?
![Evil >:D](https://www.eevblog.com/forum/Smileys/default/xevil.gif.pagespeed.ic.tdrs7Uj5gu.png)
So right about this time (no doubt since my attention had returned to the real world, as opposed to the theoretical world of ohms, bias voltages and current shunts), I notice a strong smell of "fresh-pressed cotton", and a right proper burning sensation in my junk region.
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=499154;image)
I drop my probes, push myself away from the bench, and find this dangling right at groin-level!
It's a quick & dirty light-bulb load array I'd left on the unregulated outputs the night before during preliminary troubleshooting before I pulled the control PCB. Evidently I didn't notice it there with my belly pressed against the bench, even after I flipped the power on.
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
Fortunately I was able to make an adjustment quickly enough to prevent completely par-boiled juevos; we're still a little tender, but we'll live.
![Phew :phew:](https://www.eevblog.com/forum/Smileys/default/phew.gif.pagespeed.ce.n2uLOVFYMP.gif)
So take it from the old tinker-dwagon... just because your alter-ego is fireproof, doesn't mean YOU are.
PAY. A. TTENTION!mnem
![](http://i1183.photobucket.com/albums/x462/mnemennth/TheMoreYouKnow.jpg)