Billu's thread closed

[SemperFi]

So billu's thread was closed b/c it was an offline smps design. I appreciate the fact that the front end of an offline smps is not isolated from the mains, but the secondary is isolated and fact is these are becoming more and more common. If the secondary wasnt isolated I can agree with closing it due to lethal risks.
An offline smps has more components on the mains side of the transformer and therefore potentially more dangerous, but even our old school transformers have switches, fuses, wiring, line fiilters, etc on the mains side of danger.

Shouldn't offline smps be allowed to be discussed here?

[powerbob]

Yes it should.

[nigelwright7557]

SMPS are dangerous to work on. Simply forget to switch it off, grab the pcb and you are dead.

I designed mine to have an LED on to show power was connected. Even then on tests I powered it up from the other end of an extension lead.
I have 30+ years experience in electronics and still managed to blow 3 fuses and blow out the circuit breaker twice !

SMPS are just not worth the risk, stick to linear supplies.

[palstanturhin]

Well... Linear transformers do have the primary side also...You can kill yourself with them as well - no difference in that matter between smps and linear...

[MarianB]

Originally Posted by palstanturhin

Well... Linear transformers do have the primary side also...You can kill yourself with them as well - no difference in that matter between smps and linear...

I do not agree, only a fool leaves the primary side of the linear transformer unisolated, i appologise if that offends anyone but when dealing with lethal voltages you cannot afford any mistakes, that is one of the reasons linear PSU's are much more easyer to built, they are much more safe to one's life. On the other hand ofline SMPS is a real danger to your life if you do not have the experiance to work with them, and that is why i agree fully with the rulle that closes any topik dealing with potentialy unisolated ofline SMPS, there are many solutions to isolate it properly so nothing can excuse the lack of it.

[Tony]

unless you can show that you are in fact using mains isolation transformers, then these types of threads will not be allowed.....remember, death is permanent....

[freax]

yikes, yes please censor this.

smps are not to be messed with and brung into the diy world, especially ones with components on the primary side. stick to linears for diy.

[TANDBERGEREN]

Security above all folks.

And we should not attempt to "overrule" this in any way.

[Mooly]

Originally Posted by SemperFi

So billu's thread was closed b/c it was an offline smps design. I appreciate the fact that the front end of an offline smps is not isolated from the mains, but the secondary is isolated and fact is these are becoming more and more common. If the secondary wasnt isolated I can agree with closing it due to lethal risks. An offline smps has more components on the mains side of the transformer and therefore potentially more dangerous, but even our old school transformers have switches, fuses, wiring, line fiilters, etc on the mains side of danger. Shouldn't offline smps be allowed to be discussed here?

The "secondary" output that would go to the amp wasn't what was being discussed in that thread. You were fitting and annihilating primary silicon.

There is a world of difference between wiring a conventional off the shelf transformer to the mains and attempting to build/design/modify a high frequency switching power supply that has all the primary electronics live.