Using a solid state relay :

Other Hardware General Electronics
1

Hi all,

I would like to turn on a 230V stroboscope and a sirene with a solid state relay.
On a arduino micro, max current output 20mA

I have googled and searched to no avail :frowning:

The relay I would like to use is this:

Solid State Relais - Sharp S202S02

Can I connect it like above ?

From the datasheet:

View pdf datasheet

■ Features
IT(rms)≤8A, Zero Cross type
SIP 4pin
Triac output SSR
1. Output current, IT(rms)≤8.0A
2. Zero crossing functionary (VOX : MAX. 35V)
3. 4 pin SIP package
4. High repetitive peak off-state voltage
(VDRM : 600V, S202S02 Series)
(VDRM : 400V, S102S02 Series)
5. High isolation voltage between input and output
(Viso(rms) : 4.0kV)
6. Screw hole for heat sink

■ Applications
1. Isolated interface between high voltage AC devices
and lower voltage DC control circuitry.
2. Switching motors, fans, heaters, solenoids, and
valves.
3. Power control in applications such as lighting and
temperature control equipment.

■ Design guide
In order for the SSR to turn off, the triggering current (lF) must be 0.1mA or less.
When the input current (IF) is below 0.1mA, the output Triac will be in the open circuit mode. 
However, if thevoltage across the Triac, VD, increases faster than rated dV/dt, the Triac may turn on. 
To avoid this situation, please incorporate a snubber circuit. 
Due to the many different types of load that can be driven, we can merely recommend some circuit 
vales to start with : Cs=0.022μF and Rs=47Ω. 
The operation of the SSR and snubber circuit should be tested and if unintentional switching occurs,
please adjust the snubber circuit component values accordingly.

Can I connect the an output directly to this relay or should I use additional components like a current limiting resitor.
Or do I Need an additional "snubber circuit" to have reliable operation ?

Thanks

2

On page 8 it tell's you the min is 16 mA and the max is 24 mA so at 5 - 1.2 = 3.8 a 200 ohm would be great but 160 would work to 240 ohm would work i'd go with the 200 ohm to 220 ohm

3

The LED/Arduino part of the SSR just needs a 220ohm current limiting resistor.

A snubber network goes on the high voltage side of the SSR (see datasheet).
It kills spikes and prevents false triggering.
Part values are listed in the datasheet.
Use a 600volt cap.
Leo..

4

On page 8 of the pdf, the author used the "word" (nonesuch) irregardless.

5

So irregardless the stroboscope may be ok and the sirene may cause a problem if it's something like this but 230 volt motor.

6

There are easier-to-use Solid State Relays that you can connect directly to Arduino. Example:

Make sure you read this too:
http://yourduino.com/docs/precautions_ssr.pdf

DISCLAIMER: Mentioned stuff from my own shop...

7

Thanks for the info all.

Enough info to keep me busy for a while :slight_smile: