Simple relay control... or not?

oliof

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Nightowl

'Pon my soul, @jay_s_uk, is it really that simple?

I'm not using any of those 'Out' headers, but I'm assuming I can't just copy and paste that line into my config.g file! Should I edit the line to:

M950 R0 C"exp.heater1+exp.heater2" Q100

...and connect the two wires to the relay to OUT 2?

Thank you

droftarts

@nightowl999 M950 R0 C"exp.heater1+exp.heater2" Q100 is for Duet 2. For Duet 3, use something like

M950 R0 C"out1+out2" Q100

I'm assuming your PSU is 12V, as out1,2,3 and 4 use VIN.

See here for pin names and capabilities: https://docs.duet3d.com/Duet3D_hardware/Duet_3_family/Duet_3_Mainboard_6HC_Hardware_Overview#pin-names

Ian

Nightowl

Thanks, @droftarts.

There is no PSU. I need to provide a voltage (3-14v) to operate and hold the relay (it's non-latching) and then 0v to release it.

droftarts

@nightowl999 You're running the board on USB power?

Ian

Nightowl

Sorry, @droftarts, I'm being a bit slow...

No, the Duet3 is running from a 24V PSU.

droftarts

@nightowl999 Then don't use the heater outputs, as 24V will be too much for the relay. You can use a fan output, with the fan voltage set to 12V. I would imagine the current draw of a relay is less than 2A.

Ian

Nightowl

Thanks, @droftarts. Does that mean I could use Out 7, 8 or 9 and change your code accordingly, or are they 24V because I'm using a 24V PSU?

droftarts

@nightowl999 You can use out4, 5, 6, 7, 8 or 9. Above each bank (out4-6 and out7-9) there is a 3-pin header. This selects the voltage for each bank, and can be set to V_FUSED (fused VIN, ie 24V) or 12V (using the onboard 12V reglator).

See the wiring diagram for setting: https://docs.duet3d.com/Duet3D_hardware/Duet_3_family/Duet_3_Mainboard_6HC_Hardware_Overview#wiring-diagram

Ian

Nightowl

Brilliant, thank you @droftarts!

paolozampini1973

@droftarts said in Simple relay control... or not?:

@nightowl999 Then don't use the heater outputs, as 24V will be too much for the relay. You can use a fan output, with the fan voltage set to 12V. I would imagine the current draw of a relay is less than 2A.

Ian

RELAY 20 MHA MAX 80MHA

jumpedwithbothfeet

@droftarts said in Simple relay control... or not?:

@nightowl999 Then don't use the heater outputs, as 24V will be too much for the relay. You can use a fan output, with the fan voltage set to 12V. I would imagine the current draw of a relay is less than 2A.

Ian

Isn't the maximum amps 800mA at 12V? or am I reading it wrong?

droftarts

@jumpedwithbothfeet Yes, you're right. It's 2A with V_Fused, 800mA total current with 12V. Looks like the relay is well below this, though.

Ian

jumpedwithbothfeet

@droftarts I was half hoping it was 2 amps it would of simplified my wiring a fair bit!

Nightowl

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Nightowl

@droftarts said in Simple relay control... or not?:

Just as a quick follow-up, this should work, then:

M950 R0 C"out4+out7"

...with the relay wires connected to the pins of Out 7 and the Out 7-9 jumper between V_OUTLC2 and 12V?

Thank you

jay_s_uk

@nightowl999 yep

Nightowl

Spiffing, @jay_s_uk

And then it will 'activate' with M3 and deactivate with M5.

Thank you @jay_s_uk

alankilian

@nightowl999

I just read the Amazon description for your relay-control module and it says it can be triggered by an Arduino using any voltage from 3 to 14 Volts, so you don't need to worry about drawing too much power from the onboard 12 Volt supply at all.

Where did you read that it takes 2 Amps to drive the module? I'd like to verify that.

Nightowl

Erm, I didn't @alankilian. That was @jumpedwithbothfeet wishing it was 2A!