Pages: [1]   Go Down
Author Topic: How to power 16 channel relay  (Read 165 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I want to buy a 16 channel relay. According to specs it says it needs 12v for the relay to energize. I noticed the arduino uno I am using has max output of 5v. How do I power this so the relays work?

Here is the link..... http://www.amazon.com/SainSmart-16-CH-16-Channel-Relay-Module/dp/B0057OC66U/ref=sr_1_1?ie=UTF8&qid=1403101563&sr=8-1&keywords=16+channel+relay
Logged

0
Offline Offline
Shannon Member
****
Karma: 206
Posts: 12076
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

That's not the datasheet...

It looks like it has 16 opto isolators so it takes 16 signals plus ground from the
microcontroller and a 12V supply (several amps probably) to power the relays.

http://www.sainsmart.com/arduino-compatibles-1/relay/16-channel-relay/16-channel-12v-relay-module-for-pic-arm-avr-dsp-arduino-msp430-ttl-logic.html
Logged

[ I won't respond to messages, use the forum please ]

Massachusetts, USA
Offline Offline
Tesla Member
***
Karma: 208
Posts: 8821
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Looking up the relay model number: "SRD-12VDC-SL-C" it turns out the the 'L' in 'SL' means the coil draws 0.36 W.  If that 'L' were a 'D' it would mean 0.45 W.

0.36 W at 12 V is 0.030 A (30 mA). 30 * 16 = 480 mA so your 12 V supply should provide at least 500 mA just for the relays.

The LEDs are powered by a 5V regulator running off the 12V supply so you probably need to add at least another 160 mA for those.

12 V 750 mA would probably be sufficient but  12 V 1 A would have more margin.
Logged

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

SW Scotland
Online Online
Edison Member
*
Karma: 17
Posts: 1386
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

The unit signal inputs drive directly from the arduino 5 volt signals (your linked web blurb says so).  Power for the relays and onboard components comes from your external 12 volt supply unit.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 2
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

so where do I get the 12v from? If I power board using a 12v 1  amp power supply will that work?
Logged

Massachusetts, USA
Offline Offline
Tesla Member
***
Karma: 208
Posts: 8821
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

so where do I get the 12v from? If I power board using a 12v 1  amp power supply will that work?

Yes.
Logged

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

Pages: [1]   Go Up
Jump to: