Variable resistance SSR for boil control?

[Maffew]

If you are going to have to adjust the pot to control the ssr why not just use a powerstat and be done.

http://www.alliedelec.com/search/se...powerstat|3|&gclid=CMn86aG-064CFdKR7Qod1Bokcg

 

[passedpawn]

If you are going to have to adjust the pot to control the ssr why not just use a powerstat and be done.

http://www.alliedelec.com/search/se...powerstat|3|&gclid=CMn86aG-064CFdKR7Qod1Bokcg

Variacs. Show me one that can do 30A @ 250V.

 

[Junkster]

Hah! Check it out - over 2 grand and takes both hands to adjust it!
http://www.alliedelec.com/search/productdetail.aspx?SKU=70121031#tab=specs

 

[thargrav]

So UJT is actually something real... never thought to Google and wiki now only has me slightly less confused. Sounds like 555 timers were an improvement for timer operations, but wiki still mentions ujt as part of some triac & ssr control circuits.

Does the UJT circuit provide the same control as a pmw would or does it just temporarily kill the input signal? Is the cycle timing based on the pot resistance and therefore non zero crossing or is the zero crossing in the triac circuit?

Here's the circuit for the ssr & pot from the Kyotto site.

UJT's don't work the same as a PWM. The circuit starts off every time the voltage crosses zero, wcich is 120 times a second then it turns on depending on where the resistor is set. It's non-linear with the most sensitive settings in the center of the range.

 

[WPStrassburg]

I emailed Kyotto and recieved this response this morning

Hi Walter,

KR2040AX isn't a zero or ramdom relay, it's phase control switching type.
Please see attached file.

Best regards,

-------------------------------------------------------------------
Deena Tseng
Secretary
KYTECH ELECTRONICS, LTD
No. 68, Lane 131, Sec 4, Fudan Rd.,
Pingjhen City, Taoyuan County, Taiwan, R.O.C.
TEL: 886-3-4930055
FAX: 886-3-4922455
E-mail: [email protected]
Http://www.kyotto.com
-----------------------------------------------------------------

----- Original Message -----
From: Walter Strassburg
To: [email protected]
Sent: Wednesday, March 07, 2012 2:16 AM
Subject: KR2040AX


Hello,
Is the KR2040AX SSR a zero or ramdom crossing relay? Do you have a detailed specification sheet available for it?
Thank you,
Walter

​

[FONT=新細明體][/FONT]
[FONT=新細明體][/FONT]The file that was attached was the same as the pdf I posted in the orignal link.

So what is phase control?

 

[Junkster]

This might help...
http://www.switches.machinedesign.com/guiEdits/Content/bdeee4/bdeee4_21.aspx

I don't know if this is what they mean. I almost what to get one just to play with it, but I already bought a PID and conventional SSR!

 

[passedpawn]

So what is phase control?

It's exactly what thargrav referred to earlier. They are just switching on the output somewere along the first 90° of the AC since wave.

Consider the following output vs control graph, then the sine wave graph

 

[clearwaterbrewer]

'Phase control switching type' = "Phase angle controller"?

http://homedistiller.org/forum/viewtopic.php?t=17383

 

[clearwaterbrewer]

rummaged through that thread and they are using a Newark PSR-25 for $47.74
http://www.newark.com/jsp/search/productdetail.jsp?SKU=97K7822&CMP=AFC-GB100000001

It linked to a 68 page thread..
http://homedistiller.org/forum/viewtopic.php?f=2&t=3342&start=1005

And recently one of the guys said:
"I just got a newark code for 15% off after my recent order and they said it can be shared with friends. It is "NEW2P" and expires March 31st"

so now it is just over $40, which is pretty sweet....

Passedpawn, I have to make an order for some other stuff and may get one of these just to play with... if you want to borrow to test, you are welcome...

 

[passedpawn]

rummaged through that thread and they are using a Newark PSR-25 for $47.74
http://www.newark.com/jsp/search/productdetail.jsp?SKU=97K7822&CMP=AFC-GB100000001

It linked to a 68 page thread..
http://homedistiller.org/forum/viewtopic.php?f=2&t=3342&start=1005

And recently one of the guys said:
"I just got a newark code for 15% off after my recent order and they said it can be shared with friends. It is "NEW2P" and expires March 31st"

so now it is just over $40, which is pretty sweet....

Passedpawn, I have to make an order for some other stuff and may get one of these just to play with... if you want to borrow to test, you are welcome...

Absolutely! If you need to borrow any equipment, I have extras scopes & stuff. I'd love to look at the output waveform.

 

[Berniep]

rummaged through that thread and they are using a Newark PSR-25 for $47.74
http://www.newark.com/jsp/search/productdetail.jsp?SKU=97K7822&CMP=AFC-GB100000001

It linked to a 68 page thread..
http://homedistiller.org/forum/viewtopic.php?f=2&t=3342&start=1005

And recently one of the guys said:
"I just got a newark code for 15% off after my recent order and they said it can be shared with friends. It is "NEW2P" and expires March 31st"

so now it is just over $40, which is pretty sweet....

Passedpawn, I have to make an order for some other stuff and may get one of these just to play with... if you want to borrow to test, you are welcome...

I built one using the psr-25 running a 5500 watt element and it works great.

 

[signmastr]

Anyone have any luck with one of these Kyotto SSR's, using it in a PSR-25 controller build?https://www.homebrewtalk.com/extern...088?pt=LH_DefaultDomain_0&hash=item20b9aba410

 

[fork]

I am also interested in the cheap eBay phase angle ssr. Has anyone used one successfully controlling with just a potentiometer.

 

[anicola]

I also built one using the PSR-25 a heat sink, pot, and AC ammeter. It works great. Granular control of current flow from 0 to 18 amps to my 4500 watt BK element.

 

[thargrav]

I am also interested in the cheap eBay phase angle ssr. Has anyone used one successfully controlling with just a potentiometer.

A phase angle SSR won't work with just a potentiometer. It needs a control voltage, usually 3 - 32 VDC, to turn on and we usually control these with PWM or a PID controller.

 

[Berniep]

This appears to be the same thing as a psr25 where there is control voltage built in. Looks like a nice alternative to the psr25. Plus it comes with a pot which took me a couple of tries to get right when ordering the one for my setup.

 

[clearwaterbrewer]

These units are different than what you may be familiar with, they DO just use a potentiometer...

A phase angle SSR won't work with just a potentiometer. It needs a control voltage, usually 3 - 32 VDC, to turn on and we usually control these with PWM or a PID controller.

 

[Jung4g]

Would this work as a boil control?

http://www.ebay.com/itm/1pc-KYOTTO-...088?pt=LH_DefaultDomain_0&hash=item20b9aba410

In short, as it looks like I'm the only one that actually owns that exact item, Yes, this will work to control your boil.

As many have pointed out, a PID controlled SSR is superior for a HLT or MT, but for a BK controller, this works fine and it really is as simple as putting one leg of the 240v power through it and connecting two wires to the supplied pot.

To keep it cheap, I didn't hook up an amp meter, but from what I could tell, it seemed to go from off to full power as the gauge suggested, which is all you. Really need.

Full power for coming to a boil, and then turn it down until you're just above the spot needed for a rolling boil.

I have my 5500 low density element controlled by this and haven't put it through anything but some tests, but I plan to run it tomorrow. It seems as well made as my SSRs from ECC and I have it mounted to one of their heatsinks.

I will report back if it fails ever.

 

[ajdelange]

I came in late but the way the originally discussed part would (or could) work is that there is a bridge across the triac so that whenever it is off there is + voltage available at the bridge output. This voltage charges a capacitor through a variable resistor and the cap is connected to the UJT emitter. When the UJT's firing voltage is reached the capacitor is discharged through the UJT and this burst of current is used (transformer coupled perhaps) to gate the triac causing it to turn on. By adjusting the resistor you can control how long after the triac turned off it turns on and thus the angle of conduction is controlled by the resistor setting. The triac self comutates at the end of each half cycle.

If you want turn on and turn off both at 0 crossings (and you do) then you would need a more elaborate control circuit that would decide for each half cycle whether the triac was to be fired or not. One can envision all sorts of ways to do this. What's really cool is if you have a SCR module that responds to proportional output from the controller (e.g. 4-20 loop) and smoothly adjusts the rms AC power output to follow it. This is available but expensive and, of course, is not warranted for controlling a brew pot. On/off control with a cycle time of seconds is fine.

 

[dogwolf]

you know auberin has a 25a one of these for sale with directions on how to install if your interested.its in the ssr section of there products. its like $23 not bad plus it auberin.

 

[MHZathras]

This SSR is called a Current SSR. It uses (on the input side) a 4 to 20 ma. control current.

At 4 milliamps the output connections are open all the time which would be the off state. With 20 milliamps of input current the output side would be on all the time. There is an internal voltage supply that the 0-500K potentiometer would control to give the 4 to 20 ma. required.

The output resistance is controlled between the zero (voltage) crossings of the line voltage. At 60 Hz. there are 120 zero (voltage) crossings per second. The 4 to 20 ma. of current controls when, between the zero crossings, the output is switched to a low resistance value. With 4 ma the output is not switched on. With 20 ma. of input it is switched on just after a zero crossing and thus provides maximum on time on the output. Half way between 4 and 20 ma of input current the output is switched on half way between the zero crossing supplying half of the output power capable of being delivered.

Since the output is really a TRIAC device. It is turned off (if on) when there is no supply voltage (at next zero crossing after the TRIAC is switched on). This is known as Phase Controlled Switching and will produce lots of line noise. A snubbing filter on the load is advised.

Also note the potentiometer should be wired to provide maximum resistance in the fully counter clock wise position in order to match the indications of the supplied bezel.

Hope this helps

 

[clearwaterbrewer]

stilldragon.com has 40A ones dirt cheap... look for the DIY controller, it is the SSR in that, but might as well get the whole kit, $30 or so and you get everything you need for variable boil... I know several friends with them, everyone of them is very happy... buy a spare if you are not a good electrical person, you can fry them....

 

[riverbeer]

http://www.auberins.com/index.php?main_page=product_info&cPath=2_30&products_id=353
Good price and reliable.
From Auberins, they ship from Georgia. I usually have my stuff in 3 or 4 days.
Their heatsinks are pricey, I would source them elsewhere if you want them cheaper.

 

[atoughram]

The Kyotto SSVR is what I'm using - and it works great...

The SSVR is mounted on a heat sink inside the enclosure and there is a 80mm 220v muffin fan exhausting the heat away. My only complaint is the pot is pretty non-linear - half power is closer to an indicated 80%, but I can live with that.

 

[clearwaterbrewer]

You can get everything in the pic for $31... and they work great.... I like auber's stuff, they make great stuff... but if you are cost conscious, you cannot go wrong with this... and you can buy a spare pot and SSVR and still spend less... http://www.stilldragon.com/diy-controller.html