After lots of searching last night, I’m pretty sure I found my issue being low voltage on load side of the SSR. But not 100% sure how to figure the right size resistor n exes to correct issue.
I’m working on a Lumilor project, and my test panel has four letters on it, TEST, that will all be individually controlled to light up, sequence, etc.
Now when I turn everything on the first letter will light up but stay on no matter the sequence. The other 3 letters will function as it’s supposed too.
I know from watching power supply that each letter when lit is using .030ma roughly. And my sainsmart SSR board says current needed .1-2a. The main project this is working towards will actually have each channel running 2 letters at same time on opposite sides of project. So it should come up to .060ma per channel on the final project.
How do I figure the resistor size needed? And will I need a resistor on every channel? I also read where it’s just wired in parallel on the load line out off SSR.
And in the picture I attached, I’m using a regular relay board current since it works with no issues to test coding.
I am confused when you do not provide a link to a data sheet for your SSR. Most SSR are AC only. DC SSR use a MOSFET driven by a transistor to invert the logic. What do you use the "resistor" for?
I don’t have any resistors. That’s what I’m asking what I need. To bring the load side voltage up high enough for the SSR to turn on and off correctly.
I don't think you need one. Most (but not all) SSRs have an internal resistor for the LED.
There also seems to be some driver circuitry on the board. Or maybe that's just to drive the LED. Most SSRs don't need a driver either.
I'd guess that green thru-hole part is a fuse but it could be a minimum-load resistor for the relay. Most SSRs have some leakage and they won't turn completely off without a load (or with a low-current load). Well... It's still isn't completely off but the leakage current goes through the load resistor so almost no voltage appears across the load.
Solid State Relays Common Precautions:8. Inverter Load: Do not use an inverter-controlled power supply as the load power supply for the SSR. Inverter-controlled waveforms become rectangular, so the dV/dt ratio is extremely large and the SSR may fail to release.
The SSRs need some minimum load, @johngtaxi needs a 'ballast resistor', a parasitic load,
since, apparently, his intended load is not pulling enough current.