Solid State Relay crydom td2425 uses

[GenusCanisLupus]

Hi all.
Can somebody tell me how the above unit works please. I believe from the data sheet that it converts the voltage but not 100% sure as I am still in the learning stages.
Plus any links to projects if any that use it.
Thanks in advance.
Terry

 

[Hero999]

It's a solid state relay with a DC input and TRIAC output.

A solid state relay does not convert the voltage. It enables a low current signal to switch a higher current on and off.

This type of relay has a TRIAC output. It will only turn off when the current flowing through the output falls to near zero and it has zero crossing so it will only turn on when the voltage across the TRIAC on the output is near zero. It is only suitable for switching AC.
http://www.farnell.com/datasheets/1672165.pdf

Here's a simplified schematic of what's inside an AC solid state relay:

 

[GenusCanisLupus]

Hi Hero999.
Thanks for the info.
So if I read this correctly then I could in theory use it as an power adjuster for example light dimming or motor/fan speed control, as long as they use AC power. And convert some of the AC to DC for the DC input with the use of a transformer setup.
Or have I read it wrong.  I understand roughly how triacs work.
Thanks
Terry
PS it's one of many parts I was given by my work that they were throwing out during factory move. Waste not want not lol

 

[Hero999]

It can't work as a lamp dimmer because it's zero crossing. For a lamp dimmer you need a TRIAC which can be triggered in the middle of a cycle. This solid state relay can only be triggered at the start of the AC cycle when the voltage across the TRIAC is near zero. It will then remain on until the current falls to zero.

It could be used to control a heater or turn a motor or lamp on and off.