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Topic: Solid State Relay not working for DC power? (Read 760 times) previous topic - next topic

dolanmiu

Dec 21, 2019, 08:54 pm Last Edit: Dec 21, 2019, 08:55 pm by dolanmiu
Hey,

I have bought this Solid State Relay off of eBay:



eBay link to relay is here

I am trying to control a DC power source with this relay

And it doesn't work

Is this because it's for AC power only? Or is the relay faulty?

What are my other options?

Thanks

Wawa

75volt to 264volt AC relay.

Doesn't work for DC.

What are my other options?
Depends on what you are trying to do, which you didn't tell.
Leo..

hammy

Put it in a drawer and buy something else rated for yr task

groundFungus

Perhaps a logic level MOSFET would work, but can't say for sure.  I am with Wawa, describe your use case for suggestions.

dolanmiu

#4
Dec 21, 2019, 10:21 pm Last Edit: Dec 21, 2019, 10:26 pm by dolanmiu
75volt to 264volt AC relay.

Doesn't work for DC.
Depends on what you are trying to do, which you didn't tell.
Leo..
I want to turn this on and off. Long story short, it's a power supply for an aquarium algae inhibitor, which needs to run every 10 mins:



I am aware I can use a simple relay like the below, but it would make a clicky noise every 10 mins. That's why I thought maybe a silent solid state relay would do the trick.


Paul_KD7HB

Do you see the input specs on the power supply? It says AC. So, put the SSR in series with one of the AC leads going to the power supply.

Paul

runaway_pancake

#6
Dec 21, 2019, 11:15 pm Last Edit: Dec 21, 2019, 11:18 pm by runaway_pancake
But don't hack the supply's AC (power) cord - get an extension cord and hack that instead.

> > For the sake of "safety" it's better to use/switch the "Hot" lead, don't hack the Neutral.
"Who is like unto the beast? who is able to make war with him?"
When all else fails, check your wiring!

JohnRob

As stated you could put your current SSR in series with the input of the powersupply.  However I think turning it on 6 times an hour for conceivably a long time will likely reduce the life of the power supply.

It think it would be better to switch the 12V DC side.   For a suggestion we would need to understand the load.   A simple mosfet could work well but your load might need to be isolated.  Again it depends on the load.

John


Please do not PM me with thread based messages.  If your thoughts are worth responding,  the group should benefit from your insight.

dolanmiu

As stated you could put your current SSR in series with the input of the powersupply.  However I think turning it on 6 times an hour for conceivably a long time will likely reduce the life of the power supply.

It think it would be better to switch the 12V DC side.   For a suggestion we would need to understand the load.   A simple mosfet could work well but your load might need to be isolated.  Again it depends on the load.

John



By load, do you mean what the power supply is being connected to?

If so, its connected to water. electrolysis.

it's hard to explain, here is a video:

https://www.youtube.com/watch?v=A_2ibknjDxA


aiannar974

Solid state relays are specific to ac or dc.  If on the dc side you need the dc type like this

SSR-100 DD Solid State Module Solid-state Relay DC-DC 100A 3-32V DC/5-60V DC 

raschemmel

#10
Dec 22, 2019, 02:23 am Last Edit: Dec 22, 2019, 02:24 am by raschemmel
Maybe you should skip all that and just buy this.

And of course next time, RTDD (Read The Damn Datasheet) before you order something.

dolanmiu

Solid state relays are specific to ac or dc.  If on the dc side you need the dc type like this

SSR-100 DD Solid State Module Solid-state Relay DC-DC 100A 3-32V DC/5-60V DC 
Should I buy this:

https://www.ebay.co.uk/itm/Output-5-60VDC-SSR-25DD-25A-DC-DC-Fotek-Solid-State-Relay-for-Arduino/153627027203?hash=item23c4e26703:g:wqoAAOSw-29ZW0Ca

Maybe you should skip all that and just buy this.
I am in the UK, not sure if it exists for the UK plug

raschemmel

#12
Dec 22, 2019, 05:17 am Last Edit: Dec 22, 2019, 05:24 am by raschemmel
Just use the one you bought



Post a closeup photo of the power cord, 6 inches from the end that plugs in the outlet.

Can you buy a wall outlet from a hardware store ? It's better to wire up an outlet with the SSR than cut
into the cord but it is still possible to wire to the cord but we need to see what it looks like first.

The AC SSR is wired IN SERIES with the HOT line of the AC. I don't know what they call the HOT in the UK
but in the US it is easy to tell which one it is because US outlets have a wider Neutral pin so the outlet
has a wider slot for the Neutral, thus the Hot is the narrower one.
The HOT wire of the AC cord needs to be cut and wired to the 2-pin blue screw terminal as shown in the
wiring diagram but before you do that post a close up photo of the power cord just before the plug.


SSR Wiring Diagram

I've used SSRs for projects several times but I don't like to cut the power cords because I might want
to use it somewhere else besides at home, so I always buy an outlet from the hardware store and
run series wires from the hot to the SSR and buy a plug to put on the end of the pair of wires from
the outlet. I plug the load device into my external outlet and plug my test outlet power cord in the
wall outlet. Sometimes I even add a switch in series with the hot, between the wall plug and the external outlet.

Note-Interesting product. It would have been nice to have one of those for my 75-gal salt water bubble
show tank.

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