How to connect a solenid swich using SSR?

msiriwardena

I want to connect a solenod switch( open /close about 40-50/min),I am using a SSR connected to the Prop as shown in the diagram.Do I need to place a resistor
in series when I connect to the PROP, if so what value should it be and what is the best placement.
I am connecting a Scottky diode IN5819 accross the solenoid terminals.

The circuit diagram and the SSR Omron DM0063 - specs are attached.

Thanks for your help.

Siri

tonyp12

As the SSR uses opto (LED), and it shows that it has internal resistor to limit current I say you should not use another resistor.

If you want to use a mosfet to drive the solenoid instead, here are single and duals that is up for the job.
http://www.mouser.com/Semiconductors/Discrete-Semiconductors/Transistors/MOSFET/_/N-ax1sfZscv7?P=1z0wah4&Keyword=NUD31&Ns=Pricing%7c0&FS=True


If your Solenoid is 1Amp, the mosfets mentioned above can handle it for a few seconds and after that you could switch to 50% duty at 20khz to keep it at open/close.
Pretty common to give relays/solenoid a startup boost and then lower the power to hold it.

Duane C. Johnson

Hi msiriwardena;

Looking at your diagram in Scan0001.pdf it looks like the diode wired across the solenoid is backwards.

No resister required to the Prop Pin.

Duane J

Peter Jakacki

tonyp12 wrote: »

As the SSR uses opto (LED), and it shows that it has internal resistor to limit current I say you should not use another resistor.

If you want to use a mosfet to drive the solenoid instead, here are single and duals that is up for the job.
http://www.mouser.com/Semiconductors/Discrete-Semiconductors/Transistors/MOSFET/_/N-ax1sfZscv7?P=1z0wah4&Keyword=NUD31&Ns=Pricing%7c0&FS=True


If your Solenoid is 1Amp, the mosfets mentioned above can handle it for a few seconds and after that you could switch to 50% duty at 20khz to keep it at open/close.
Pretty common to give relays/solenoid a startup boost and then lower the power to hold it.

As for the cheaper device the problem here would be if software turned it on but did not PWM as it should, then the result would be magic smoke. As for the PWM frequency that should be kept much lower due to slow turn-on and turn-off of the Mosfet unless you use a gate driver. If you did PWM use a frequency about 1kHz or even less. One way to guarantee that software could not leave the device turned on full is to use capacitive coupling.
However, I use cheap dual Mosfets in 8-pin SOIC packages such as the older FDS6990 etc that drive large solenoids directly from the Prop without any fuss.

msiriwardena

Thanks for your help.My real conern was whether I required a resistor,You all answered that issue.

Thanks again.\
Siri