Yet another thread about power controller build

[Drunk-N-Smurf]

Thanks. Off to Home Depot for more wire I go.

[rad14701]

You should never "dry fire" any electronics circuit... All component testing, like potentiometers, resistors, etc, should be done before they are installed... Even a light bulb is better than nothing for testing...

[Drunk-N-Smurf]

You should never "dry fire" any electronics circuit... All component testing, like potentiometers, resistors, etc, should be done before they are installed... Even a light bulb is better than nothing for testing...

Very true. Which I was attempting to do, just didn't realize that the ssr required a load to test. I always verify my components prior to install, and also after to ensure nothing odd happened during soldering or screwing down. Most things I can test with my meter, or if I need a load, I use test lights, or other "readable" methods.

I did think to find a lamp for testing last night, but it seems my house is nothing but led lamps.....I'm not sure when that happened...was ready to use my drill to test when I got my answer.

But, your right.

[lampshade]

Is it important to match the controller output polarity with the input polarity?

For example, say that the input cord has a hot wire and a return wire. Should the jack, on the output cord, be connected so that its hot and return wire connections match the input? In other words, let's say that the input hot wire is connected to the SCR. Should the the output jack be installed so that its hot side is also connected to the SCR, or does it matter whether the return wire from the output jack, instead, is connected to the SCR?

I hadn't thought that the output polarity makes a difference since I assume that the heating element is only a resistor. But I am also using the boiler from a T500 rig and maybe there is more inside the boiler than just a heating coil.

The reason I ask this is that my output jack recently burned up. When I replaced this jack the SCR fried. I later discovered that I had reversed the polarity of the hot and return wires on the replacement output jack. So I'm left wondering whether output polarity does make a difference. Or maybe it only makes a difference when using a T500 boiler.

[lampshade]

Well, I think I have found the problem. I plugged my T500 boiler into a wall socket and the boiler no longer heats. Ignore my above post.

[newbietoo]

Like many others, I am also curios if there is an estimated price, as well as a parts list.
Your build looks great. Very nice work.

[rad14701]

The short answer is, No, AC polarity isn't important in most instances, and a heating element won't be effected... However, if you want to do things properly and in accordance with electrical codes, Yes, you want to keep the Hot and Neutral consistent throughout the circuit...

[Andrew_90]

So back to the pots.

I have a commercial 5 000W SCR Controller which is controlled by what appears to be about a 2 or 3W pot of undetermined value. I need to open the unit up to measure. The control is way to coarse and I was considering a 3 turn pot as a work around. I like the idea of inserting a trim pot however.

A couple of questions;

Should the pots be Log of Lin?
What wattage should the pots be?

[Andrew_90]

The short answer is, No, AC polarity isn't important in most instances, and a heating element won't be effected... However, if you want to do things properly and in accordance with electrical codes, Yes, you want to keep the Hot and Neutral consistent throughout the circuit...

I think polarity IS important. You always want to switch on the Live for safety sake.

[shadylane]

Should the pot be Log or Lin?
What wattage should the pots be?

Linear if you want 50% power when the knob is halfway.
You don't want a pot with an "audio taper"
It's made to compensate for the human ear.

The wattage depends on the controller design.
Some call for a pot rated at 5 watts. some say 2w

[Andrew_90]

Thank you kindly.