Home
JAQForum Ver 24.01
Log In or Join  
Active Topics
Local Time 23:03 02 Aug 2025 Privacy Policy
Jump to

Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.

Forum Index : Microcontroller and PC projects : How to switch 1000W 220V with uMite

     Page 2 of 2    
Author Message
Paul_L
Guru

Joined: 03/03/2016
Location: United States
Posts: 769
Posted: 09:51pm 19 Nov 2017
Copy link to clipboard 
Print this post

  MicroBlocks said  If it is on for long times there might be problems with a SSR as it will probably get hot. That is my main concern. Or is that wrong? A 1000W (about 5A on 220v) seems not that much and i could always use a beefier version.

Does a triac or SSR rated for 20A get hot at all when used with 5A?
A triac could get hot if you don't use an adequate heat sink. These triacs and the zero crossing driver both cost less than a dollar. The only thing I can suggest is to play around with it.

Paul in NY
 
Quazee137

Guru

Joined: 07/08/2016
Location: United States
Posts: 593
Posted: 11:31pm 20 Nov 2017
Copy link to clipboard 
Print this post

@Tinine Thanks was going to try the SSR's on a project next year
and knowing there is a leakage current is very good thing to know.

They may have wanted the zero crossing ability of the SSR passed on
to the opto-coupler.


@MicroBlocks This may sound odd but on an old Z80 based aluminum
roller press they use a triac to slowly ramp up a relay was switched
on to hold it. Then on power down they switched off at the zero crossing.
For months they kept losing the triacs even with heat sinks as the over
all system created a lot of heat.

Here is an old project in line with what your doing.
sous-vide-machine-you-can-make-at-home


And here is the data you wanted
2017-11-21_111652_SSR_Thermal_Considerations.pdf


Quazee137


Edited by Quazee137 2017-11-22
 
Tinine
Guru

Joined: 30/03/2016
Location: United Kingdom
Posts: 1646
Posted: 10:17pm 22 Nov 2017
Copy link to clipboard 
Print this post

  Quazee137 said   @Tinine Thanks was going to try the SSR's on a project next year
and knowing there is a leakage current is very good thing to know.

They may have wanted the zero crossing ability of the SSR passed on
to the opto-coupler.


Nah, this was DC and we're talking a few mA. According to the SSR data-sheet, the leakage shouldn't have been sufficient to drive the opto...but it was.

They just didn't want me changing stuff because they never had a problem with the servo drive that failed. It was a different brand and obsolete and I have to believe that the same signal input, simply had a lower impedance.
 
     Page 2 of 2    
Print this page


To reply to this topic, you need to log in.

The Back Shed's forum code is written, and hosted, in Australia.
© JAQ Software 2025