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Electronics => Beginners => Topic started by: netdudeuk on November 20, 2016, 07:55:27 pm

Title: Carlo Gavazzi 10 A rms Solid State Relay
Post by: netdudeuk on November 20, 2016, 07:55:27 pm
Hi

Is it fair to say that the below SSR would be ok for use in the UK, to be driven by a TTL level microcontroller output ?

http://uk.rs-online.com/web/p/products/4790634/ (http://uk.rs-online.com/web/p/products/4790634/)

The plan would be to put the outputs in series with a socket and the mains supply via fused plug.

I'd then plug in a lamp or whatever as required.

Thanks
Title: Re: Carlo Gavazzi 10 A rms Solid State Relay
Post by: Ammar on November 20, 2016, 08:07:17 pm
Yep, looks fine for your purpose.
Title: Re: Carlo Gavazzi 10 A rms Solid State Relay
Post by: Gyro on November 20, 2016, 08:10:51 pm
Yes, it should be fine from the mains perspective - as long as you mount it in a suitably earthed metal enclosure and ensure earth continuity from input to output. If it's a lamp load then I'd put a 3A fuse in the plug. Don't fit a 13A fuse as it will exceed the max rating of the SSR. Also ensure that the logic circuit feeding it is earthed as an added precaution.

I note that the minimum control voltage is 4.5V, which is cutting it fine. A TTL level wouldn't be sufficient but a 5V CMOS (74HC etc) might. To be on the safe side I'd feed the logic into an open collector transistor and feed it from a higher voltage (the unregulated input to your 5V regulator for instance).
Title: Re: Carlo Gavazzi 10 A rms Solid State Relay
Post by: newbrain on November 20, 2016, 08:57:16 pm
Quote from: Gyro on November 20, 2016, 08:10:51 pm
I note that the minimum control voltage is 4.5V, which is cutting it fine. A TTL level wouldn't be sufficient but a 5V CMOS (74HC etc) might. To be on the safe side I'd feed the logic into an open collector transistor and feed it from a higher voltage (the unregulated input to your 5V regulator for instance).
In the datasheet it's actually specified as 3V, for the RS1A23D10 model, so not much to worry on that front.

On the other hand, consider that an heatsink is more or less mandatory according to the tables in DS page 3 (the "Apply silicon paste" in the picture is quite a hint...), maybe it's possible to do away with it for much less than 1A, but not recommended (40 K/W  Rth j-a).
The minimum operational current of 150mA (~35W) might be a problem with light loads.