09-11-2020 10:32 AM
Hello guys ,
im new to the community. Im working on a project on mydaq board and i want to control a mini pump through it.Actually just turn it off and on nothinge else. The pump operates between 6-12v with 540mA . My question is : a simply ss relay 5v with max 1A is enough ? or is it dangerous and i should use something like a diode to protect the mydaq board? if so can you describe how? Could you suggest maybe a better solution for the problem?
09-11-2020 10:38 AM
Hi Katsanik,
@KatsanikJr wrote:
The pump operates between 6-12v with 540mA . My question is : a simply ss relay 5v with max 1A is enough ?
What kind of SSR do you want to use?
How do you want to connect it?
Which signals of the myDAQ do you intent to use?
Which kind of power supply do you want to use?
Have you thought about placing a fuse somewhere in your circuit?
09-11-2020 10:53 AM
I found these specs on the relay that im looking for
I want to connect A0 output from my daq to the relay . And i will have an external source for the pump which will also be connected with the relay. So the signal which controls when the relay is open or close will come from the A0 output . Not considering fuse
09-11-2020 12:19 PM
Hi Katsanik,
@KatsanikJr wrote:
I found these specs on the relay that im looking for
- Rated coil voltage: 5V DC
There is (atleast) one spec missing: what is the needed coil current to actually switch the relay?
Is your myDAQ able to drive that current using any AO or DO channel?
Have you considered an external amplifier (a simple MOSFET will do) to drive the relay?
09-11-2020 01:35 PM
Sorry i am new to the circuit logic. As far as i can understand you suggest me to use both mosfet and the relay so the mosfet will open the relay and the relay will open the pump?
09-11-2020 04:17 PM
I also tried to take as example this one https://forums.ni.com/t5/Example-Code/Turn-on-a-DC-Computer-Fan-using-a-Solid-State-Relay-myDAQ-and/... . So instead of the cooling fan which operates at 12VDC i have the pump but im not sure if my thought is correct
09-12-2020 03:52 AM
Hi Katsanik,
that example is "quite ok".
The point is: they took a certain kind of SSR, but you decided to use a coil-type relay ("electromagnetic").
Their main difference (from myDAQ point of view) is the current they need to actually switch the output contacts.
You still missed to provide the specs I asked for: how much current does your relay need and is your myDAQ able to deliver that current?
09-12-2020 03:37 PM
Hello again ,
and thank you so much that you actually helped me understand the problem. As i understood: mydaq can provide through output ports a max 0,2mA current. But the relay i am using needs more current in order to open the coil. So i have to figure out a way on how to find that current . So i figured out something else : im gonna use a mosfet which is on in low current (low voltages) and an external source connected to the pump with a flyback diode to protect the mosfet.
So i provide volt through mydaq in mosfet and mosfet will work as a relay.