Arduino Forum

Using Arduino => General Electronics => Topic started by: jonisonvespaa on Feb 06, 2013, 12:39 pm

Title: Whats the best method to switch 4 relays from 1 output?
Post by: jonisonvespaa on Feb 06, 2013, 12:39 pm
hi
id like to switch 4 * 5v relays switching 4 * 230v feeds,  from just 1 output from my 328

just wondering what is the best way / method for doing this?

thanks
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: Krodal on Feb 06, 2013, 12:56 pm
1-wire i/o expander ?
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: jackrae on Feb 06, 2013, 02:57 pm
4 relay coils in parallel with one common driver transistor ?
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: fungus on Feb 06, 2013, 03:02 pm

1-wire i/o expander ?


Also known as a "transistor".
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: Krodal on Feb 06, 2013, 03:19 pm


1-wire i/o expander ?

Also known as a "transistor".


No, something like this : http://www.maximintegrated.com/datasheet/index.mvp/id/3818

But now I'm confused. Should the relays be controlled seperately ? Or are they activated all at the same time ?
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: MarkT on Feb 07, 2013, 01:16 am
Or step a uniselector (!)
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: retrolefty on Feb 07, 2013, 01:20 am
One 4PST relay?

Lefty
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: jonisonvespaa on Feb 07, 2013, 09:17 am
think my best / easiest option is to use one transistor switching 4 coils in parallel, thanks for the help
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: michael_x on Feb 07, 2013, 01:20 pm
Are your 4  230Vdevices ultimately fed from the same power line ?
Why don't you want to run them in parallel from a single relay ?

Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: jonisonvespaa on Feb 07, 2013, 01:23 pm
hi micheal , no the 230v's are seperate live feeds fused to 3a each which turn on various things
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: michael_x on Feb 07, 2013, 01:57 pm
A single 4PST relay is about the same price, but more compact, than 4 separate "ordinary" SPST ones, or 2 * DPST as an intermediate solution.
( http://www.newark.com/panasonic-ew/s4eb-12v/power-relay-4pst-12vdc-4a-pc-board/dp/46F5824 )

If you need a 2PST per line, I'd go for four relays anyway.

Edit: oops, you need 5V relays, so there's not too much choice ;)
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: jonisonvespaa on Feb 07, 2013, 02:17 pm
i did think of doing it that way but not much choice on 5v, i  wanted to make it bomb proof, i intend using a 8a dp contacts doubling up on those  giving me 16a
cheers
Title: Re: Whats the best method to switch 4 relays from 1 output?
Post by: krupski on Feb 07, 2013, 04:21 pm

i did think of doing it that way but not much choice on 5v, i  wanted to make it bomb proof, i intend using a 8a dp contacts doubling up on those  giving me 16a
cheers


If you need to turn on or off four different 230 VAC circuits AT THE SAME TIME but keep them isolated from each other, use solid state relays:

(http://www.crydom.com/en/Products/Catalog/PicturesCategory/SSC.jpg)

These little modules have optical isolation, take in 3 to 20 volts DC at a few milliamps (TTL levels) and can control 230, 460 and more volts at 25, 50 and more amperes. They are completely isolated, so you can wire one end to an Arduino and the other end directly to a load safely.