# can 240 V AC be converted to DC

can single phase AC be converted to DC ?

can you draw 20 amps from it once converted ?

1. Sure, that what they do in your TV set, computer, radio, etc.
2. Have a look on a breaker panel, if it allows 20 A.

would you get 240 V DC 20 amps ?

if you don't know, what is the breaker panel, ask you local electrician.

Single phase 240 V can supply 20A from normal domestic wiring

the breakers are usually set at 16 amp for a 3 pin plug

if you wire direct to the consumer unit - ie an electric oven or shower

you can pull 32 or even 40 amps with the correct thickness cable

Note here we are talking about a power of 4.8 KW, this is a very lot of power.

If you have to ask these questions then you should not be messing with such a circuit, it is for ultra experts only.

Note that 240V AC mains is a peak voltage of about 340V and a peak to peak voltage of 680V.

the application is an electric brake

the application is an electric brake

For what exactly?

That's some damn big thing you have in your house needing a damn big brake - got a train line through your house?

240v AC after rectifying will get you about 339v DC, so to get 240v DC you will need a big big transformer.

er - and you're gonna control this with an Arduino? :scratches head:

You could control the rotation of the galaxy with Arduino.

I'd like to see you try.

what would people recommend instead of an arduino ?

There is nothing wrong with the arduino for controlling this. You have not mentioned needing anything outside the scope of an arduino. Why do you think you want to change? The issue people have is with the vast amounts of current and voltage you want to switch, this is not going to be any easier with another processor.

If you use on of these http://www.alperton.ie/alperton/Files/SEW%20BMG%20Brake%20with%20BSR%20relay%20wiring%20diagram.pdf and replace the current-relay marked (2) with a contact of your arduino-controlled relay you have a perect brake controller. No need for rectifier, it's all in the BSR..

If the application is an electric brake, then surely the power comes from a motor/generator set, not the mains? So why 240V?

an eddy current produces the braking force

however you need to supply the magnetic field

20,000 N can be held back if you can get enough power

240V x 20A is a massive electromagnet - is this to stop a train? Braking force is proportional to velocity squared and also to mag field strength squared. For low velocity braking you use a motor not an eddy-current brake.

Hello, I am an electrician. Please explain what you need this for, I may be able to help with choosing the correct application.