I was wondering about the differences in capabilities of MOSFET switches vs opto-isolated SSRs. Can both use PWM to achieve dimming/speed control?
Specifically, how would something like this
compare to something like this?
Please note that I am only talking about solid state relays, obviously, not mechanical.
No. SSR's only work with AC. You can do AC phase angle PWM though, just like an old fashioned light dimmer. If you have a way to measure line phase, that is...
relay module is not the same as solid state relay.
relay module are not useful for any PWM purposes.
but to make a choice what to buy first think what do you want to do and which device can do this, then you can looking for control for this device.
There are DC solid state relays are there are "zero crossing" AC relays that turn-on (and off) at the AC zero-crossing so those won't work in dimming applications. Those are better for motors or other inductive loads.
DC solid state relays are usually made with MOSFETs (and an opto-isolator).
AC solid state relays are usually made with TRIACs (and an opto-isolator). A TRIAC latches-on until current falls to zero (i.e. the AC zero-crossing) so they are not usable with DC.
Unlike regular electro-mechanical relays, AC & DC solid state relays (usually) aren't interchangeable.
...A few years back I use 7 DC solid state relays instead of MOSFETs because it was "easier". The whole thing is in an insulated package so I didn't have to add any resistors make any calculations or carefully select the MOSFET and they "just worked" (and they are still working). It probably did cost more than MOSFETs -and I didn't actually need the isolation.
This was a 7-channel lighting effect where the lights are turning on-and-off frequently and rapidly so I didn't want regular relays constantly "clicking" and maybe wearing-out. MOSFETs would have worked fine!
So can or can't a solid relay pwm 12/24v with a 5v trigger? I am confused.
First, the links you referenced are not for a MOSFET nor Solid State Relay.
There are two types of SSRs. The most common is for controlling the AC line (mains) .
There are DC SSR's but they are not very common. They would LIKELY allow you to PWM a device.
I'm guessing you want to operate a MOSFET but without dealing with the soldering etc. If so look a things like the link below.
A VERY QUiCK look at ebay found this board.
110v or 220v AC motors or AC lamps?
No.
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