DIY stuff and electrical safety.

[Alana]

There are few topics related to electrical safety on this forums but none of those discusses DIY devices like home made power supply.
I see that DIY is basically "you use it at your own risk" but i was wondering how to make this risk as low as possible. Care to discuss the subject, possibly using examples of good and bad design?

[cthree]

I think your best bet is to recycle a safe power brick from some other perhaps obsolete device as a mains to DC converter for your variable DC supply. A wall wort or external brick can also be purchased from a distributor such as Digikey. That will keep AC mains outside of your project and make it run cooler and make it smaller on your bench. Most importantly, it will make your project safe.

[c4757p]

All discussions of safety on this forum always become arguments about safety. There are a million ways to do it, and mine is right, goddammit, you're all just idiots! Not sure if we could actually accomplish this.

[cthree]

All discussions of safety on this forum always become arguments about safety. There are a million ways to do it, and mine is right, goddammit, you're all just idiots! Not sure if we could actually accomplish this.

I agree.

 

[Paul Price]

C4757P


Bravo!  people are ´so lame as to just pontificate their opinions.

What makes a wall wart power so damn dangerous you cannot use it safely withouit a license from the paranoia orthodoxy!

[SeanB]

All these are basically saying is "Ask if you are not sure, and if you are sure ask anyway", or use the grey stuff between the ears and think before you turn it on, and do some basic safety checks before and during construction.

[KD0CAC John]

A big part of getting info ,is to so supply info with the question .
What are your needs for a power supply , we need to know in witch direction to go ?

[Rasz]

think of all the bad things that can happen
-short
-power spike
-lightning
-cat pee
-pulling more juice than rated
-pulling max rated juice
-room temp

now think how it will affect your psu, can it burn a house? can it pass line voltage down to the device it is trying to power?
then you have interferences - will it prevent your mother in law from listening to Sermons on the radio (dont know if its a bad thing tho ), how about power factor? other supplies on same line?

best to just get a ready made psu and be done with it just avoid chinese crap

[c4757p]

My safety rule (emphasis on the lack of an "S" at the end of "rule"): Do you understand how, where and why electric current flows (capacitors aside...)? Then use your brain and think for yourself. You can figure out what can or will go wrong. No? Then remember Darwin, or he'll remember for you.

[Alana]

My safety rule (emphasis on the lack of an "S" at the end of "rule"): Do you understand how, where and why electric current flows (capacitors aside...)? Then use your brain and think for yourself. You can figure out what can or will go wrong. No? Then remember Darwin, or he'll remember for you.

Basic stuff like this is covered but i have doubts about preventing some fault conditions and i would like to ask you about details, possibly posting schematics and pictures of my devices.

[Todd]

All about circuits has a pretty good writeup on electrical safety.  Its worth a read before doing something involving mains electricity.

http://www.allaboutcircuits.com/vol_1/chpt_3/1.html

[c4757p]

Well, I'm suffering from serious "tl;dr syndrome" today, but that does look well put together.

[Bored@Work]

All discussions of safety on this forum always become arguments about safety. There are a million ways to do it, and mine is right, goddammit, you're all just idiots! Not sure if we could actually accomplish this.

No, the fun starts when the "Safety? Fart it, safety is for wimps! Aren't you man/woman enough to take a few electric shocks?" brigade comes out. Or the "But it is cheap, Dude! I don't care if I am dead, as long as it is cheap, dead cheap." brigade.

[c4757p]

True.