Author Topic: Solid state relay that will turn off when the primary voltage is removed.  (Read 1420 times)

0 Members and 1 Guest are viewing this topic.

Offline Jim-0000Topic starter

  • Regular Contributor
  • *
  • Posts: 65
  • Country: au
I have a small collection of solid state relays. They all trigger the secondary "contact" to conduct when the primary is excited with (in this case) 12 volts.
However, they stay on after the primary voltage is disconnected.
By "stay on", I mean the secondary terminals remain in the closed condition for some time, many seconds, maybe a minute sometimes.
Question:
Can some one suggest a solid state relay for low voltage/current, that has the properties where the secondary follows the primary?
In other words, the secondary "points" open again, after closing, when the primary actuating voltage is removed or switched off.

Jim.
 

Offline Zero999

  • Super Contributor
  • ***
  • Posts: 20357
  • Country: gb
  • 0999
Yes, it sounds like the original poster is using a TRIAC based SSR on DC, which will only turn off, when the secondary power is disconnected.

You need a MOSFET based SSR such as the PVG613.
https://docs-emea.rs-online.com/webdocs/140c/0900766b8140cdcb.pdf
 

Offline Jim-0000Topic starter

  • Regular Contributor
  • *
  • Posts: 65
  • Country: au
Thanks for the replies Blueskull and Zero.
 

Online NiHaoMike

  • Super Contributor
  • ***
  • Posts: 9319
  • Country: us
  • "Don't turn it on - Take it apart!"
    • Facebook Page
If it helps, SSRs for 12-24V DC are often sold as "3D printer MOSFET modules".
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Cryptocurrency lesson 0: Altcoins and Bitcoin are not the same thing.
 
The following users thanked this post: Jim-0000

Offline Jim-0000Topic starter

  • Regular Contributor
  • *
  • Posts: 65
  • Country: au
It turned out that a simple 4N25 opto coupler did the job that I wanted in this application.

https://www.futurlec.com/LED/4N28.shtml

Thanks for all the good replies.

Jim.

 

Offline Psi

  • Super Contributor
  • ***
  • Posts: 10384
  • Country: nz
If it helps, SSRs for 12-24V DC are often sold as "3D printer MOSFET modules".

I think those are mosfets with an opto included on the PCB.
That's different to an SSR which provides isolation without any requirement to 'power' the module itself.
Greek letter 'Psi' (not Pounds per Square Inch)
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf