Power-out LED on continously

[denny]

I wanted to see the LED power on from a farther distance on my MYPIN TA4. So I connected a generic panel mount LED between the SSR pin 3 and SSR pin 4, which should show (to me, at least) when the SSR is sending current to the heat element. It does, but it is on ALL THE TIME. Is this because there is a constant idle current of a few mA across those SSR pins? LEDs are very low drain and I'm thinking it may be enough to light the LED. If so, how could I make this work? Use a higher value resistor? A different type LED? Other problems could be, increasing the resistor might cut down the brightness to the point of blinking in time with the 60 hz AC and therefore still not showing when the element is actually on--? Perhaps I need a bulb of some sort that would not fire with such low current? Or maybe use a relay to control it that needs more than a few mA to engage? But then it might cause the bug-a-boo of cycling too rapidly (short life)? And maybe I can't do this as easily as I thought or even not at all! I guess it's plain to see I'm confused......I just hope you can understand what I'm trying to describe.

 

[JckDanls 07]

It's on all the time because pin 3 is hot all the time... I'm thinking you need to be on pin 4 with the black wire and to neutral with the white wire (from the light) ... pin 4 is only energized when the SSR tells it to... pin 3 is supplying the feed at all times ...

 

[denny]

Duh!! Simplicity at it's finest! OK, I owe you...

Reminds me---Charlie Brown is trying without success to get his kite airborne. His thought bubble is filled with many mathematic, algebraic, and engineering formulae. Lucy is also flying a kite, way, way up there. Her thought bubble is "2 + 2 =4".

 

[denny]

Jack, your idea still looks good, but when I wire that way, my add-on 12v LED doesn't lite, although my fan (the load) pulses and runs slowly. Now my LED is 12v and to drive it, I used a 12v output, 110v input power supply. The line input of the power supply is connected to SSR pin 4 Jack and the neutral to ground. Since the SSR voltage available is only 3 to 32vdc, and my PS is 110vac, I have a problem right off the bat. Well, I eliminated the PS entirely, connected the LED between SSR pins 3 and 4 and it worked! I don't know if there are any hazards to doing it this way but it works, at least for now. Hopefully someone will speak up if they see a fault or error

 

[JckDanls 07]

ok.. I'm confused... maybe some pictures or a wiring diagram ... Didn't know the light was 12 volt .. so you have the Pos. and Neg. from the PID to the Pos. and Neg. terminals on the SSR ?? That will be a low voltage signal.... In your original post you said a heat element was being used.... in your last reply you say a fan ... Heat element being 110V. ?? Fan being 12 V ?? And LED light being 12 V. ?? What is the fan used for when you have electric heat element ??

The SSR is going to be turning on/off very rapidly (several times a second) when smoker gets close to temp and will continue to do that to hold set temp...

 

[denny]

Ok, here is a diagram if I can make this work. This shows when I had the 12v PS in the circuit for the LED. I removed the PS entirely and connected the LED directly to SSR pins 3 and 4, pos to pos, neg to neg. It works, with the LED pulsing, just as expected.

BUT, is there a constant idle current across SSR pins 3 and 4, even if the PID isn't signaling for them to close (thereby causing current to flow to the element from pins 1 and 2), and might that make the add-on LED glow all the time? I may be wrong and need to be corrected. A little knowledge can sometimes make things worse!

Please note that initially I was referring to my test set-up but didn't make it clear. The fan I referred to was a temporary LOAD, in lieu of the ultimate 110v heat element. I apologize for my unclear comments which caused confusion. I really appreciate your hanging in there with me!

 

[JckDanls 07]

ok.... something doesn't look right with the SSR wiring... Only one wire (hot) will go to both the supply side (#2 in drawing IF that is supply side) of the SSR and also to the PID... The other wire (common) will only go to the PID and the Heat element, NOT back to the SSR (#1) as you have it in your drawing ... #1 from the SSR will only go to the other terminal on the heat element...

Here is a basic wiring diagram.. https://www.smokingmeatforums.com/threads/temperature-controller.286355/#post-1949620

what is the 12 V. PS... what's the PS stand for ??

My confusion was the connections on the SSR.. I thought you were trying to wire a 110 V light to the Switched side of the SSR

 

[denny]

Thanks for the really quick reply!

It seems to me that our diagrams are mostly the same--just mirror images of each other. I have AC in going to PID 1 rather than PID 2. Yours has AC going to PID 2 rather than PID 1. I think either way is OK as polarity isn't involved.

If I can explain it properly, the real difference lays with yours showing the neutral connecting to the heating element UP FRONT. In mine, neutral is not used until the very end, after going thru the heater. Sort of like a long connection in series.

I'm on really thin ice here as my knowledge, such as it is, is based only on what I learned to get a general class ham license back in the early 60's, aided by a lot of tinkering since. So don't take this as arguing! I have a problem with making this PID work, and I'm saying all this to help you understand how I'm looking at it so you can straighten me out!

I am going to rewire it following the diagram you gave me and will let you know the outcome.

Finally, a couple other points. PS in my usage, probably ancient history by now, means power supply. And to show how dense I am, I just don't understand why connecting my add-on LED to SSR 2 won't work--assuming the LED gets the right voltage. Here's why--when SSR pin 2 is energized, the heating element will heat, so why couldn't that same signal turn on something that will power my LED? Please tell me how I'm wrong! And thanks again for your patience and forebearance.

Denny

 

[JckDanls 07]

you are correct... polarity doesn't matter on the PID.. what I am seeing in your drawing is that both pins 1 and 2 on the PID are going to both pins 1 and 2 on the SSR... that is not correct ... Using AC in on #1 is fine and also going to #1 on the SSR is fine ... Your #2 (common) is where the problem lies... going to the PID is fine (as it should) but it can not go to #2 on the SSR.. It has to go straight to the heat element (or vise versa, from element to PID)... #2 pin on SSR goes only to the other side of the heat element....

 

[denny]

Keith, thank you. I believe I've got it straight, but...please try to follow my thinking here, step by step:
Hot AC goes to PID 2 and SSR 2--
Then, neutral goes to PID 1 (in my world it is coming from the other end of the element)--
SSR 1 goes to hot side of element--
Does this look correct to you? This description follows the schematic you sent, hot AC going to PID 2, etc, rather than PID 1 in my drawing. I haven't tried it out since I have been so wrong so many times before. You probably wouldn't know but I can tell you embarrassment is painful to live with!

 

[JckDanls 07]

Yes.. this sounds correct... just double check the SSR pins 1 and 2 to make sure it's not directional (in one side and out the other)... I believe it can go ether way... I'm just trying to go by memory (we all now how terrible that can be) from when I did mine...

 

[denny]

Here I am, asking you for help, and I make you visualize a circuit I am describing, rather than show you a diagram! (In my defense I should say that the whole process of sending a pic from my camera to you is something I have to relearn everytime!). So here is the latest diagram, if it goes thru. Well, looks like it did.
Wired just as shown, except with TC plugged into PID 7 and 8, the PID doesn't come on!
Voltage checks between PID 1 and 2, OK
PID 2 to gnd, OK
PID 1 to gnd, open
SSR 1 to gnd, open
SSR 2 to gnd, OK
SSR 1 to SSR 2, OK
(OK means connection.)
I checked the PID with a separate AC line to PID 1 and 2 and it lights up.

I give up. Do you see anything amiss in the diagram?

 

[JckDanls 07]

The only thing I can see wrong (in wiring diagram) is the SSR is wired to where the TC should be... but I wouldn't think that would keep PID from working...

 

[denny]

Yes, I made an error on the drawing--the TC goes on pins 7 and 8, not 3 and 4!! However, I did at least wire it correctly!
With frustration almost at the apoplectic level, I disconnected and reconnected every screw and several solder points this morning. At the ground terminal strip, I finally found one screw connection that was INTERMITTENT, and mostly without contact! Put everything back together and damned if it didn't work!!! When you said you didn't see anything wrong with the drawing, I knew that either I was demented or the problem was in the assembly and went from there.

Just being able to talk with someone receptive and knowledgeable made all the difference. I can't thank you enough but thanks again anyway! I'll probably hook it up with the actual smoker tomorrow and give it a go with a nod to you!
Denny

 

[JckDanls 07]

Good deal.. glad we got it worked out...