ULN2803A for driving pneumatic solenoids

[raman00084]

i am using dspic30f6010a 5v ds pic for controlling 20 different solenoids that controls a pneumatic piston. generally i use optocoupler and mosfet irfz44 for driving the solenoids that works perfect without any emi are noise problem. my doubt is can i use ULN2803A for controlling the solenoids the solenoid current is 200ma 24v will there be any problem in long term run kindly guide me which one is best and noise free

thank you

regards
kalyan

 

[paulfjujo]

hello



specsheet data

The collector-current rating of each Darlington pair is 500 mA.

and , for global comsumption

Total substrate-terminal current . . . .. . –2.5 A

you have 8x200 mA => 1,6A !

Could be OK ..

Take care about over voltage.. (Max 50V)
Add anti-retour diodes accross Solenoides valves ..
or use "COM pin" linked to +24V


If you allready tested a reliable solution (Photocoupler + IRFZ44) ,
i think it is better to keep this principle.
If one ULN out of order means 8 solenoid valve out !

the best is the enemy of the good !.