I bought a six channel SSR to operate one motor and few solenoid valves with my Arduino UNO.
Reason for this purchase? I was experiencing too much undesirable noise with my conventional Relay.
Upon using it I experienced the latching effect as was troubling this guy, and upon going through the complete forum thread I was confused. Why can't my SSR switch DC when the markings on the back say DC also along with AC.
If I can't switch DC with an SSR and my regular relay is creating noise in tune of 7 ADC values shift with each relay switching on, then how do I remove this noise?
I can't see anything on the page you linked to that says these SSRs are capable of switching a DC load. If they are AC only SSRs, that would explain what you are experiencing. AC SSRs normally contain a triac which will only switch off when the load voltage is zero (which occurs 100 or 120 times per second with an AC load).
Please explain what DC load you are trying to switch. Have you considered logic-level MOSFETs?
@PaulRB I did give logic level MOSFETS a try long time back. Can't recall why it didn't work. Then Shifted to TIP122 transistor, but there was still lot of noise and that too unpredictable noise. With a Relay at least the noise is predictable (Roughly 7ADC increment on switching each relay on) and can be mathematically minimized. How would you suggest to sort this out? I am using 6V motors and solenoid valves.
A backward step. TIP122 is a Darlington transistor, an older technology with high voltage drop, not very suitable for 6V.
What is the coil resistance of these motors and solenoids? How many of each are you using and how many can be active simultaneously? What PSU are you using? Do you have flyback diodes and noise suppression caps across the terminals of the motors and solenoids?
