finding a suitable SSR

[fetmosfet]

Dear All,

I am working on a circuit where i use 5V from my digital pin of arduino to control a 12 Circuit. The 12 V circuit would have max current of 500mA. I would like to know a Solid State Relay (SSR) that I can use for the switching.
I would not use a normal relay as i want quick and frequent switching.
I tried using Mosfets, but it just heats up too much and also that I would want an NC too possible with SSR.
Kindly suggest me an SSR for both NC and NO.

Thanks in advance!

Have a nice day.

 

[(*steve*)]

solid state relays are only available as NO.

Mosfets may be a better solution. If they were getting hot then you were probably doing something wrong. Perhaps you can explain your application a little better.

What are you switching (voltage, current, and type of load) and how quickly do you want to switch it?

 

[fetmosfet]

Thanks steve for the reply.

My application might seem a little weird but i am sure it will work.
I am using Max7219 multiplexing IC with arduino but this time to drive 64nos. of 12V LEDs.
Driving normal LEDs is very easy and I have done it a lot of time, but to drive 64 nos of 12V LEDs power supply becomes an issue for me. I intend to make an 8x8 grid as i would do with normal LEDs, Then connect 8 SSRs to segment points and 8 SSrs to Digit points.
Important thing i noticed is Digit points are always high and the LED Cathode is attached to it, so it lights up when the Digit points go LOW. Here using a Transistor or a MOSFET becomes difficult for me. I can easily use a Transistor or MOSFET on the Anode side of LED, i.e. the Segment side.
I then think that an SSR could be a solution as t=I can connect it to any side, anode or cathode.
Hope you understand my explanation.
Sorry if all this seems weird.
Other solutions are also appreciated.

 

[(*steve*)]

You use N channel mosfets (or NPN transistors) for low side switches and P channel mosfets (or PNP transistors) for high side switches. You may need to invert the outputs to properly drive the mosfets.

Maxim even publish instructions for you: http://www.maximintegrated.com/en/app-notes/index.mvp/id/1196

You will lose the ability to control the LED current using the 7219 though.

 

[fetmosfet]

Dear Steve,

Thank You very much.
This is of great help to me. I googled a lot and even youtube in this matter but did not get something of much help.
This link that you have shared with me seems really helpful and I surely will try and get back to you.

P.S.: your subtitles say Thermodynamics... I found it thought provoking to see that word in an Electronics Forum.

 

[(*steve*)]

Glad to have helped.

You'll understand my sig if you hang around until the next crowd of over unity folk arrive.