Well, I'm starting a new project and would like some help figuring out the requirements and some pointers to how and go about doing this.

Region Free Power Supply
Input:
100Vac - 240Vac
50/60H

How can I handle this wide range of input voltages?

 

Every cell phone charger built in the last 10 years has no problem doing this. I can go to my local thrift shop, and buy all the retired cell phone chargers I can carry for $0.50 each....

 

Every cell phone charger built in the last 10 years has no problem doing this. I can go to my local thrift shop, and buy all the retired cell phone chargers I can carry for $0.50 each....

Yes, this is true, but how can I handle this? Do I first use a transformer?

 

Its not so easy to do it properly.
Even if it may work, you get a surge, and your circuit blows up instantly.
And it produces too much EMI eventually it may not cause trouble to you but may setup some old analogue television or high end audio equipment or prevent a wireless device from working.

Most fake chargers do work just not properly, or not as well as the genuine brand charger.

Indeed, you can make a power supply with just a 1000uH RF inductor, the LED display + PIC light up fine. No filters no fuse no surge protection just plain nothing.

Its not recommended to sell it like that. Better buy a ready-made power supply. The good ones are quite costly, the cheapest electronic transformers occassionally just blow up with multiple components failing. Most chargers work fine but mind it- they are probably plugged in a few percent over a year.

If you use them to power something permanently, you'll see about surge events and explosions for no reason at all.

Its also bad because its dangerous. Even if you think of many of the dangers, you may not notice a few or just one. Fires can be caused, explosions, and electric shocks.

Some day I just made two windings on a ferrite core transformer, connected with a PI switcher IC, that was it, worked. No calculations of any kind.

Played around with a TRIAC too (we have 240 volts here which isnt funny if you touch it).

If you dont even know if you need a transformer or not, I'd not recommend to work with high voltage. Even if it looks fine and works, things may go wrong later.

You need a qualification of an electrician or the equivalent, or better stay away from it.
Even just installing lamps and so forth, for each 10,000 people you get so and so accidents.

 

Yes, this is true, but how can I handle this? Do I first use a transformer?

If you expect to discuss it on this forum, then yes, you need a transformer.

This is not a project for a newbie. It requires may specialized components and techniques that the average homebuilder doesn't have. I would start by tracing out the schematic of some existing chargers/power supplies...

 

First read the NEMA code, read it again, and again, until you are quite familiar at least with what you are dealing.

Most people making high voltage circuits get minor shocks regularily, mind that, there are some precautions so you dont get a major one.