No-Break Switch 2 Way Circuit

"Break", as in your thread title, is to open a circuit (in the electrical sense).

"Brake", as you used in the body of the post, would be to bring something to a stop, as in DC Braking as it might apply here.

Please clarify.

But are you asking about battery isolators? If so, read this:

http://www.bcae1.com/battiso.htm

Yes, what I need to make is a UPS Uninterruptible power supply. I will chek the link you sent.

Thanks for your answer.

OMG!!!!!!!!!!!!!!!!!Just buy one!

Yes, there can be.

Try "make before break" switch.

So why cant the charging system stay connected while the batteries are being loaded?

Because when a power cut occurs, the batteries must supply AC power for the office.

Why? What - all of it?

This is already the norm in sensitive electronic systems which require battery back-up.

A simple circuit would have incoming AC power supplying a battery charger and a power supply. The power supply puts out "x" volts DC to the equipment. The battery charger supplies "x-1" volts DC to the batteries.

Place a diode in-line between the batteries and the power supply.

The slightly higher power supply voltage reverse biases the diode, preventing current flow from the battery.

When the power supply fails, the batteries will instantly (practically speaking) power the load.

Then I need: 1.-The diode. 2.-An DC to AC converter. 3.-And a rellay circuit?.

Thanks for your answer.