Question about analog control SSR

Many like to post about a first successful ferment (or first all grain mash), or first still built/bought or first good run of the still. Tell us about all of these great times here.
Pics are VERY welcome, we drool over pretty copper 8)

Moderator: Site Moderator

Post Reply
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Question about analog control SSR

Post by artooks »

Hi Everyone,

I have been reading about SSR controls, but I do not seem to find the what I am looking for so I wanted to ask, for the last 2 weeks, me and my friend are building a controller, by the way my friend is quite knowledgable about circuits and diagrams which helped me a lot, he is also very good at programming micro controllers, anyway, what we built is an element controller with an SSR, and he specifically built a circuit which triggers the SSR on and off. This has an oled where I can see at what percentage I want the element to be on and off and he programmed it for a total of 100 sec for each period and this is divided into 4 sections each at 25 sec so if I bring the digital pot to %50 that for every 25 second it stays on for 12.5 sec and 12.5 sec off, because he says that this SSR can only work by triggering 5 volts where brings my question in the forum I mainly see an SSR and a analog potentiometer hooked up to the SSR so as far as I know SSR only works on and off is this true so if I bring the the pot half way does it stay on and off %50 or behaves more like a dimmer, I am trying to understand the difference between an analog and numeric potentiometer can someone please explain in simple terms. Because my friend says this analog pot cannot work like this I showed him "SD's" element controller, so I am a little bit confused and want to clarify this, thanks.
Mooki
Novice
Posts: 3
Joined: Thu Sep 07, 2017 12:39 am

Re: Question about analog control SSR

Post by Mooki »

Not sure I quite understand what you and your friend have built, especially the part about 100s period divided in 4, which are also divided in 2... :?:

SSR is a Solid State Relay, can be either ON or OFF, the normal operation for power control is to "pulse" the ON-time.
I suspect that your friend has programmed the controller to change state every 25s if necessary - this is very slow for power control IMHO. I'd probably go for 1s.
As far as I know the differences between an analog and digital pot should not affect usability with an SSR, a digital pot has a number of fixed values vs analog having basically every possible value between min and max.
Of course, the pot is not connected directly to SSR but is used to set duty cycle in controller.
Pikey
Site Donor
Site Donor
Posts: 2444
Joined: Sun Oct 16, 2016 3:29 pm
Location: At the edge of the Wild Wood

Re: Question about analog control SSR

Post by Pikey »

I'm with Mooki, an SSR is a solid state Relay and is on or off - unless it's a Solid STate RECTIFIER like a thyristor. Mostly Power control is done using 2 solid state rectifiers back to back so one operates on the positive half of the ac wave and the other on the negative half. These can be bought in a single package called triacs. Firstly we need to know what you have bought here.

With a triac the trigger voltage can be adjusted with the potentiometer, so thhat the switching time can be made longer or shorter. The pulse frequenct cannot be adjusted since that is totally dependent on the mains frequency and is 100x per second if your mains frequency is 50 Hertz. It is the pulse width which is varied, so the amount of electric getting to your heating element is completely adjustable from 100% to 0%. This is pretty much analogue and will work very well - they are used in washing machine motor speed controllers an the like. in suitable sizes, most of us who run electric stills are using them.

[Edit used like this they are called "Pulse width modulators" ]

This "on-off " you refer to does not sound as though it is going to work properly in a still, since it will behave like an electric hotplate - which are a real pain.
User avatar
Yummyrum
Global moderator
Posts: 7596
Joined: Sat Jul 06, 2013 2:23 am
Location: Fraser Coast QLD Aussie

Re: Question about analog control SSR

Post by Yummyrum »

There are two types of SSR commonly used .
The type that is used with a pot is an SSR vr and is a special device which is basically a light dimmer on steroids . It is not really a solid state relay at all . It is a dedicated phase controller in a blob of plastic which has no isolation between its control element ( the pot ) and the output it controls ...... Why it is called a solid state relay is a joke IMHO .

The SSR da on the other hand is truely a solid state relay with isolation between the control curcuit ( your mates curcuit that contols it) and the output output it drives .

Personally I prefer the method your mate uses as it has the ability to more accurately control the power in a gauranteed way .

But ...way your mates done it is not the best way. ....The on/off time is too long. He should be able to get it to do the same thing but with a cycle of around a second so that its on for a percentage of a second and off for the rest . That will avoid surge boiling of the wash .

This type of control is known as burst fire control and has in th past been able to be achieved with a simple pulse with modulator running at around 1Hz -2Hz directly controlling a SSR da

Your mates version sounds good in that you can see the power on a display but I thnk he needs to up the rate to as close to a second to reduce the surge boil issue .

An improvement on the burst fire method is the "time proportional " method .
This is where a controller chip ... Auduino ... micromite ... rasperry what ever can really come into play . The "smarts " calculates the most efficient proportion of time on and off to get a certain powerm control

EG . Say you wanted 75% power with burst fire you might turn on SSRda for 1.5 seconds and off for 0.5 seconds .
A far cry from what yo have ..... but with proportional control the SSR da is being switched on for 3 cycles per second and off for 1 cycle .

This means that there is negligble surge activity. . ..... it does mean a bit more programming .... but shit .... whatmer don't like a challenge .. . Or .... you could. get you self this http://www.auberins.com/index.php?main_ ... cts_id=560" onclick="window.open(this.href);return false;" rel="nofollow
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Hi,

What we have used is an SSR 50 Amp, it is not a SSVR so just to simplify, I would like to give an example,

If I bring the dial to 50% the controller behaves like this.

Every stage is 100 second, and there are four intervals

For 50%
for the first 12.5 second it stays on
then 12.5 second off

this is 25 seconds in total and it does 4 like this to complete the 1st stage the it goes to the second and does the same thing,

so it means that, at every 100 second it stays on for the 50 second an off for 50 second if it is set to %50 at the begining, today I tried it with only water to see how it behaves,
I purchased the camco incoloy element 02929 it is actually a 4500 Watt element but I could only get 3200 which is a good thing since I wanted a small one, the only thing I am wondering
If I will be able to adjust the number of drips with this setup.
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Here is my new controller
Attachments
rsz_img_1709.jpg
User avatar
shadylane
Master of Distillation
Posts: 10344
Joined: Sat Oct 27, 2007 11:54 pm
Location: Hiding In the Boiler room of the Insane asylum

Re: Question about analog control SSR

Post by shadylane »

artooks wrote:Hi,

What we have used is an SSR 50 Amp, it is not a SSVR so just to simplify, I would like to give an example,

If I bring the dial to 50% the controller behaves like this.

Every stage is 100 second.....
....so it means that, at every 100 second it stays on for the 50 second an off for 50 second if it is set to %50 at the begining.
Nice build :thumbup:
100 seconds might be too slow of a cycle time.
The still might surge :oops:
User avatar
Yummyrum
Global moderator
Posts: 7596
Joined: Sat Jul 06, 2013 2:23 am
Location: Fraser Coast QLD Aussie

Re: Question about analog control SSR

Post by Yummyrum »

OK so it sounds like you are using Time proportional control . I still think the time period is too long and you will get surging .See if your mate can change the code so it does the same thing but faster .

Olddog , one of the ledgends here recons he still had noticable surging with on/ off rates around 1 second , so at 12.5 seconds you will have problems
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Hi,

Today I have tried this controller for the first time, I hooked up to the mains the when the element was on it showed 3200 Watt because I am in Turkey the electricity here is 220 whereas my element is 240 Volt and also the hertz here is 50 and in US I think is 60 so my Element draw 15-16 amps and was working around 3000W-3200W, so I wanted 1000Watt and set the controller to 32% as my starting point, but when I start to see the drops it was just you described, when the element was on the output was coming very fast and when it was off it was nearly stopping so this did not work as I anticipated, so now I would like to ask the question, as far as I can see many people are using an SSVR and a pot, but the pot itself cannot drive the SSR so this is not an SSR it is a Solid State Voltage Regulator, but When I look at the SD store they sell an SSR with only a pot which confuses me, so as far as I can see the power should not be cut at all but it should be lowered, which an SSR cannot do because they all work on and off am I right ?,

I decided that I should buy an Auber DSPR1, there are some questions that I would like to ask.

It says that it is a Power Regulator with a knob so is it a dimmer, but It says it controls an SSR and SSR works on and off so how could it be a dimmer, on top of that it says that it has two working modes.

1) Burst Firing Mode
2) Time Proportional Mode.

So which one is being used in distilling and this will attach to an SSR,

My main target is I want to be able to control the Power (Watt) with the rotary so does this Auber DSPR1 is able to do that, I appreciate if someone could simplify this as I am quite confused due to my lack of electricity.
User avatar
still_stirrin
Master of Distillation
Posts: 10329
Joined: Tue Mar 18, 2014 7:01 am
Location: where the buffalo roam, and the deer & antelope play

Re: Question about analog control SSR

Post by still_stirrin »

Artooks,

You're in the wrong forum for these questions. Look in the Related Electrical Accessories forum. There is much discussion there, in particular this thread which outlines the SSR build (and functionality).
http://ww.homedistiller.org/forum/viewt ... 85&t=56390

Try using the HDGoogle search in that forum for answers to your specific questions. But indeed, attempting to reprogram the duty cycle longer than one second is your downfall. It is not dynamic enough to keep pace with the delicate boiling process.
ss
My LM/VM & Potstill: My build thread
My Cadco hotplate modification thread: Hotplate Build
My stock pot gin still: stock pot potstill
My 5-grain Bourbon recipe: Special K
RedwoodHillBilly

Re: Question about analog control SSR

Post by RedwoodHillBilly »

still_stirrin wrote:Artooks,

You're in the wrong forum for these questions. Look in the Related Electrical Accessories forum. There is much discussion there, in particular this thread which outlines the SSR build (and functionality).
http://ww.homedistiller.org/forum/viewt ... 85&t=56390" onclick="window.open(this.href);return false;" rel="nofollow

Try using the HDGoogle search in that forum for answers to your specific questions. But indeed, attempting to reprogram the duty cycle longer than one second is your downfall. It is not dynamic enough to keep pace with the delicate boiling process.
ss
Agreed. If you want to use a standard SSR (most likely a zero-crossing type) your controller should really have a zero-crossing detector as an input to your controller. This will let you synchronize the SSR to the line frequency. Then look at different algorithms such as burst mode control, etc. These discussions are beyond the scope in this forum. Your "controls" guy needs to do some homework.
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Thanks RedwoodHillyBilly,

So as far as I understand There are two types of SSR so for example which SSR's are used only with a simple Pot, do they called SSVR ? I remember your controller so what you have in your element controller is it Solid State Voltage Regulator ?

Thanks
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Thanks you SS,

I will move it to that category thanks for reminding me.
Pikey
Site Donor
Site Donor
Posts: 2444
Joined: Sun Oct 16, 2016 3:29 pm
Location: At the edge of the Wild Wood

Re: Question about analog control SSR

Post by Pikey »

Or just buy one of these or something similar - there's loads of them out there and they do just what you want without any surging. Piece of cake and dead cheap !

http://www.ebay.co.uk/itm/10000W-Electr ... Sw2tRZcdSN
artooks
Trainee
Posts: 893
Joined: Mon Mar 13, 2017 9:48 am

Re: Question about analog control SSR

Post by artooks »

Hi,

We changed the program of the circuit, now the cycle time is 10 seconds which works in 4 stages every stage consists of two on off parts so now it is like:

1.25 sec on + 1.25 sec off -- 1.25 sec on + 1.25 sec off --1.25 sec on + 1.25 sec off --1.25 sec on + 1.25 sec off --

The total is 10 seconds, now I can get it work nicely I counted the drops

100 drops in 44 seconds which is 2.3 drops in 1 sec is that a good number, I guess so but even with this somewhere at the cycle the drops is coming very slightly fast then it gets levelled but overall the outcome is much much better.
Post Reply