What I plan to do with this is to run 3 SSRs with heat sinks to run two heating elements and a coolant water system. I would like to run the SSRs without the TPO and use the PWM. I should not burn up the SSRs with vented heat sinks, in hopes of improving the PID response.
As I am not savvy with C++, so I am concerned I would break the code if I simply "//" all the code the tutorial deemed a part of the TPO. Any thoughts? Thanks.
AFIK. Using PWM with SSR's isn't ideal, because they only turn on or off during AC zero crossing points, so the output you get would probably not be what you want
You probably need a "dimmer" system using triacs if you want phase based control, and even then its not normal PWM, its based on triggering the triacs at the appropriate point in the 50Hz (or 60Hz) mains waveform, to give you the appropriate duty cycle.
BTW. Why are you doing it in such a complex way. Surely people have successfully done this before?
You can use SSR for temperature control, in fact thats what they are made for.. BUT you have to use a long PWM period, 10s is standard. So the built in PWM of the arduino is not suitable because it is too fast.
@nilton61
I got the impression from the OP's posting that he thought he could do PWM dimming using SSRs
I should not burn up the SSRs with vented heat sinks, in hopes of improving the PID response.
I'm not sure why he needs to use vented heat sinks either. This doesn't seem to be related to PWM etc, as either the SSR is On or its Off, its not an analogue device that will dissipate a lot of heat because its operating in Class A , B or C amplification modes.
Its effectively a mode D amplifier of a sort.
nilton61:
You can use SSR for temperature control, in fact thats what they are made for.. BUT you have to use a long PWM period, 10s is standard. So the built in PWM of the arduino is not suitable because it is too fast.
Thanks. The tutorial and other related forum readings seemed like they indicated this was do primarily to a heat issue. I will need to research PWM more to understand the speed issue.
I'm not sure why he needs to use vented heat sinks either. This doesn't seem to be related to PWM etc, as either the SSR is On or its Off, its not an analogue device that will dissipate a lot of heat because its operating in Class A , B or C amplification modes.
Its effectively a mode D amplifier of a sort.
I won't claim to know understand half of the fancy stuff you said rogerClark, you sound like you know what your doing I am using the heatsinks as I am running 1500W heating elements, 13.63 amps, of folks on Amazon complained of their SSRs burning up without the heatsinks. Perhaps they were using simple on/off controllers and were simply left on too much. Hard to say.
I may have to leave the code unchanged, hell it will likely work even if it is not as responsive as I would like, so I will go reasearch the PWM concept more.
I am using the heatsinks as I am running 1500W heating elements, 13.63 amps, of folks on Amazon complained of their SSRs burning up without the heatsinks. Perhaps they were using simple on/off controllers and were simply left on too much. Hard to say.