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Topic: How to power 16 channel relay (Read 628 times) previous topic - next topic

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

MarkT

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

johnwasser

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.
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jackrae

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.

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

johnwasser


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


Yes.
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willytwo

I just bought the 16 channel relay board too.
I see there are 5v and ground pins next to the 16 channel pins.
I'm assuming that I should plug the 5v and ground from my Arduino into these terminals as well.
Am I correct?
Or are they power out to the Arduino board?
It sucks that there is no documentation for this board.

willytwo

I just bought the 16 channel relay board too.
I see there are 5v and ground pins next to the 16 channel pins.
I'm assuming that I should plug the 5v and ground from my Arduino into these terminals as well.
Am I correct?
Or are they power out to the Arduino board?
It sucks that there is no documentation for this board.

woodygb

#8
Dec 19, 2014, 07:42 pm Last Edit: Dec 19, 2014, 07:44 pm by woodygb
I just bought the 16 channel relay board too.
I see there are 5v and ground pins next to the 16 channel pins.
I'm assuming that I should plug the 5v and ground from my Arduino into these terminals as well.
Am I correct?
Or are they power out to the Arduino board?
It sucks that there is no documentation for this board.
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

Scroll down to where it says....

Quote
Click to Download the Manual

michinyon

It appears from the schematic that the device creates its own 5V supply from the 12V supply.

If this is so, it's not obvious why you would be connecting the 5V connection to the Arduino.

Maybe you can use it to power the Arduino.

And as for "click to download the manual",   if you actually do this,  there is no manual.

Some sort of PCB track image,   and a schematic,  which is rather confusing.   The  control inputs seem to be active low,   which is not what you would expect from the description.

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