Pages: [1]   Go Down
Author Topic: Relay to drive low voltage from high voltage  (Read 800 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 14
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Can a relay also work the other way around, like high voltage circuit driving a low voltage circuit? If so, please provide me a link to such a product.
Logged

Left Coast, CA (USA)
Online Online
Brattain Member
*****
Karma: 331
Posts: 16514
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Can a relay also work the other way around, like high voltage circuit driving a low voltage circuit? If so, please provide me a link to such a product.

Sure, it the coil voltage of the relay is rated for use with the 'high voltage circuit' value you are working with AND if that HV circuit can spare the extra current the relay coil will draw. The output contacts can be used with any voltage/current that is within the maximum voltage/current ratings for it's contacts.

Lefty
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 14
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

My motiv is to detect if the circuit is in close or open state. The idea is to use the NC relay connected to the 220V and the drive the 5V to the Arduino when the current is flowing.

I did try to look for such relays with coil voltage 220v, but couldn't find. Please do provide me a link if you know one.

Thanks.
Logged

Left Coast, CA (USA)
Online Online
Brattain Member
*****
Karma: 331
Posts: 16514
Measurement changes behavior
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Well they are certainly available from major electronics suppliers and even E-bay if you search around.

http://www.ebay.com/itm/JQX-13F2Z-AC-220V-Coil-10A-240VAC-28VDC-8-Pin-DPDT-General-Purpose-Relay-/300790758823?pt=LH_DefaultDomain_0&hash=item460886bda7

Lefty
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 14
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks.
Logged

Topsham, Vermont USA
Offline Offline
Edison Member
*
Karma: 23
Posts: 1759
... in The Woods In Vermont
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi, Another often-used solution is a optoisolator chip driven from the 115/230V and it's output to Arduino.

There are a couple shown here: http://arduino-info.wikispaces.com/Popular-ICs

See: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=45&t=9617 for an example. There are better circuits using a capacitor in the input circuit; I'll look.
Logged

Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

Pages: [1]   Go Up
Jump to: