the OP said:I noticed that there is a mention of wall wart as alternative to the DC SSR setup.
Do correct me if I understand it wrongly,
1. A wall wart with volt control of 0 to 10v will be used.
2. The positive end of the wall wart is connected to the positive output of the DC power supply and the negative end of the wall wart is connected to the “PAR” input of the DC power supply (GPS-3030)
How do I connect the potentiometer and a 75watt wire wound resistor to this setup?
You really want to ignore this stuff. Initially I didn't realize that the controller provides a current limited voltage to turn on a LED or OPTO DC SSR, so let's stay simple.
The "wall wart" would have taken the place of the internal current limited supply (the 27 V) and/or provided power for the home made circuit that was decided would be abandoned. I have still been thinking about it. A nice linear very low current bi-polar +-15 V supply is the easy way out for the circuit that's gelling around in my head with no actual components attached.
"WE" never really told you how to connect an external voltage source to control the power supply nor have I tried to decipher the master/slave stuff. For now, it's unimportnant.
the OP said:on the other hand
If I use a DC SSR, how do i connect it to the system with the PID and 75 watt wire wound resistor?
If you can connect a LED, you can connect the SSR. Take the 12 A version of the SSR here: https://www.omega.com/pptst/SSRDC100V.html. but you are probably on the other side of the pond than me. I think you mentioned your mains voltage of 220/240 or so. Farnell may be a source for the SSR.
One side of the SSR would connect like a LED. Note that it also has a built-in LED too. The specs of the SSR are incomplete too, but that company I've used before because it's a lot of different manufacturer's under one roof or a one-stop shop. They used to re-label their stuff. So a fluke thermometer would be come an Omega thermometer. So, observe the polarity when connecting the LED side. The datasheet is here: https://www.omega.com/temperature/pdf/SSRDC100V.pdf
Note that the input (LED side) and the output side have polarity markings. Earlier I told you how to connect the LED side.
So now think of the output side that also has polarity markings. It MAY be useful to use a fuse sized for the expected load, but it would just act like a SPST switch (observe polarity) using the output terminals of the power supply. So, everything goes in series. PS+Fuse+SSR+resistor in any order observing the polarities You would be able to set a lower voltage to get finer temperature control. The fuse, strictly isn't needed.
So, this way you would be applying brief power to the resistor at the front panel voltage setpoint of the power supply. The SSR will have some series resistance. If it gets hot, it needs to get heat sinked.
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