My Power Controller
Posted: Sun Mar 18, 2012 4:01 pmI have read much about power controllers on various forums, probably too much, frightening me in the process and making me delay the construction. Now that I have made one, I do not know why I was so concerned. It was very straightforward.
I chose to go, what I thought, was the easiest route. For this method I needed two pieces of kit.
1)A solid state relay (SSR) of the correct type, I chose this one
Click here for Details
2) A Potentiometer. I chose this one.
Click here for Details
AS the controller is being used for large power heating elements the SSR will get hot and cease to work.. Cooling the SSR appears to be a bit of trial and error and the methods range from clamping the SSR to something big and cold or using cooling fans.
Not wanting the aggro of trying one method to see if it worked, I opted for a belt and braces approach, bolting the SSR to a heat sink with heat transfer paste and then blasting it with a couple of computer cooling fans. It works. I have boiled a kettle for an hour or so without it getting overly warm.
Click here for Details of Heat Sink
I put the bits in a box with a couple of outlets – and just to make it look better, added a couple of meters and that’s it.
Click the picture for a larger view
It took about five minutes before the novelty of watching the meters wore off. After that, it was a case of just winding the knob on the potentiometer to “about there”. Adding the bigger dial and longer pointer takes the guesswork out of what the setting was the last time and makes the process a lot more repeatable.
If anyone is interested in the inside of the box and the wiring let me know.
I chose to go, what I thought, was the easiest route. For this method I needed two pieces of kit.
1)A solid state relay (SSR) of the correct type, I chose this one
Click here for Details
2) A Potentiometer. I chose this one.
Click here for Details
AS the controller is being used for large power heating elements the SSR will get hot and cease to work.. Cooling the SSR appears to be a bit of trial and error and the methods range from clamping the SSR to something big and cold or using cooling fans.
Not wanting the aggro of trying one method to see if it worked, I opted for a belt and braces approach, bolting the SSR to a heat sink with heat transfer paste and then blasting it with a couple of computer cooling fans. It works. I have boiled a kettle for an hour or so without it getting overly warm.
Click here for Details of Heat Sink
I put the bits in a box with a couple of outlets – and just to make it look better, added a couple of meters and that’s it.
Click the picture for a larger view
It took about five minutes before the novelty of watching the meters wore off. After that, it was a case of just winding the knob on the potentiometer to “about there”. Adding the bigger dial and longer pointer takes the guesswork out of what the setting was the last time and makes the process a lot more repeatable.
If anyone is interested in the inside of the box and the wiring let me know.
).
