Wiring/potentiometer question

[raven_r_one]

Hi all

I'm still in the early stages of wiring up my controller (using a PSR) and I'm scratching my head a bit.

I've added a voltmeter (more to confirm the thing is on than anything else) and with no load, the potentiometer gracefully swings the needle through the range. I haven't wired in the PSR yet, so it's just the switch, potentiometer, gauge, and an outlet on the back.

Two questions:

1 - With the knob turned all the way down, I can never get exactly zero volts.
2 - I hooked up a light bulb and with that in play, now the needle shoots up and down and the potentiometer seems to not be working so smoothly anymore.

Any suggestions?

I _think_ I can post pics - will those help?

[skow69]

Yes, pics would help, but I wouldn't be concerned until you put the final load on it. Resistance controlled voltage is totally load dependent. Finish it, hook it up, and then check it. If the meter is inaccurate then we can troubleshoot it. Before that, you are just chasing ghosts.

[bellybuster]

if you don't have your SSR connected yet, what do you have power going thru???

[Soggy Bottom Boy]

.... I hooked up a light bulb and with that in play, now the needle shoots up and down and the potentiometer seems to not be working so smoothly anymore. ....

Things that make you go, .....Hmmmm

How much of a load were you drawing directly through the pot, at what voltage, and what is (or was ) the pot rated for in watts?

....and, did you let any of the "magic smoke" out of your potentiometer?

[aquavita]

Man I hate when the magic smoke escapes.

Really think that someone needs to develop better magic smoke containment devices.

[raven_r_one]

Before I go further - yep! I didn't have the PSR hooked up.

Potentiometer seems ok.

I wired up the PSR, but no bueno. Voltmeter didn't even move at all, so something is wrong.

I tested with a handheld voltmeter and there's current flowing.

I will try and post some pics, any help would be appreciated...

[raven_r_one]

Here we go.

I'm also in the States if it matters.

[raven_r_one]

So power (120v) comes in via black to the switch, then from the other side of the switch, to one side of the PSR.

Then from the other side of the PSR, it goes to the voltmeter then on to the outlet wired in back.

The white wire goes from the wall to the voltmeter to the outlet.

The potentiometer goes from one one side/leg to the middle leg through the switched side of the PSR.

[bellybuster]

your SSR is a voltage controlled SSR, you need a resistance controlled SSR. You can see your requires 3-32 volts for operation

[bellybuster]

you can see here that the control (terminal 3&4) is resistance instead of voltage


the one that you have is intended for operation via the output of a PID

[Soggy Bottom Boy]

.

Just .......WOW!

[raven_r_one]

Thanks bellybuster!

This one?

http://www.amazon.com/gp/aw/d/B008DFWV4 ... SY165_QL70" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

Thanks bellybuster!

This one?

http://www.amazon.com/gp/aw/d/B008DFWV4 ... SY165_QL70" onclick="window.open(this.href);return false;" rel="nofollow

Yes, that one... It requires a 500K potentiometer in case that isn't what you have on hand...

[raven_r_one]

Rad/bellybuster - thank you both!!!!

Yes Rad - I manage to do that much right...

Guys - I also have some of these lying around:

Is it worth taking the PID?

[bellybuster]

a beer brewer would kiss your fine ass for that box....

[raven_r_one]

But would it work for the SSR I already have

It's used to reflow mother boards...

[bellybuster]

yes, I assumed the SSR came from that box.

[bellybuster]

oh hang on, you're not talking using the PID for stillin are ya? Doesn't really go to well, PIDs work on temp and stills don't. It can be done but unless you know the ins and outs of setting the PIDs up for manual....

[raven_r_one]

Blarg - yeah - was just going to use it instead of the potentiometer...

[raven_r_one]

And nope - I messed up and ordered the wrong thing.

Going to order the right one, not sure I want that PID anyway.

Feel like that's just going to add a level of difficulty I don't need right now.

[raven_r_one]

Or is this a better option?

http://www.amazon.com/gp/aw/d/B008MPK4I ... w_sbs_hi_2" onclick="window.open(this.href);return false;" rel="nofollow

[skow69]

Yeah, that will do it.

[raven_r_one]

Ok - got all the new things (and maybe more).

Hooked up an incandescent lamp and perfect!

Potentiometer totally works flawlessly. I can go from off (and zero volts) to full and 110.

I added a fan (110-115 volt - blows directly on the heat sink) and a light (easy to tell if the thing is switched on).

One question though - the ammeter registered nothing. Didn't even budge.

This means the light is drawing a tiny amperage? Or does it mean I have a borked ammeter?

[raven_r_one]

That was derpy...

Amps = watts/volts

So:

60/110 = .5 amps.

Which won't even register on a 30 amp ammeter.

Is that assumption correct?

[raven_r_one]

Better question, is there a good way to test the ammeter.

I'm a few weeks away from having my kettle ready to use, really don't want to accidentally dry start this element.

[bellybuster]

Do you have a little electric heater?
Otherwise, don't worry about it, you have a volt meter for now and when your kettle is done you can find out for sure. Lots of folks have no meter at all.

[raven_r_one]

How about a router?

[raven_r_one]

Ran it tonight - worked a charm!

Thank you EVERYONE who helped me and answered all my stupid questions!

P.S. - fan on psr is awesome because you can turn down the element with the potientiometer and have the fan continue to cool the psr.

[bellybuster]

Ran it tonight - worked a charm

Great!
Isn't running electric fantastic?!

[skow69]

Congratulations. It's been quite the ride. Time to enjoy the fruits of your labors.

Skol,
skow