Build yourself a cheap digital boiler power regulator

[Druncan]

Well explained write up, well done!
I would love to see someone do the next stage where you control a Buffalo 3kw ind hob by temp with a PT or smartPid hack,,,

 

[Fil]

Well explained write up, well done!
I would love to see someone do the next stage where you control a Buffalo 3kw ind hob by temp with a PT or smartPid hack,,,

how is the induction hob controlled?

 

[Druncan]

It has a dialled knob with 26 steps. I have found the part as a replacement https://www.nisbets.co.uk/buffalo-control-panel/ad153
Could this be replaced with a digital controller from a PID? happy to buy one and send it to those who know the dark digital electrical science,,, :thumb:

 

[Simonh82]

It has a dialled knob with 26 steps. I have found the part as a replacement https://www.nisbets.co.uk/buffalo-control-panel/ad153
Could this be replaced with a digital controller from a PID? happy to buy one and send it to those who know the dark digital electrical science,,, :thumb:

I'm in the middle of a very slow kettle RIMS build using and Inkbird PID and non-digital controller as per @Bigcol49 design. In the back of my mind, I was thinking about a future upgrade to a 50L kettle and 3KW Buffalo induction hob. If I did that, I thought I would keep the PID for temperature control but use the buffalo hob to control the power during mashing. @Druncan, why can't you just use the built-in power control on the Buffalo hob? I guess the PID would be constantly switching the hob on an off which it may not like.

 

[BeerCat]

Finally got around to wiring one of these up to an STC1000. Will give it a test tomorrow with the mash. My PID needs a serious retune so looking forward to trying this out. :)

 

[AdeDunn]

Finally got around to wiring one of these up to an STC1000. Will give it a test tomorrow with the mash. My PID needs a serious retune so looking forward to trying this out. :)

I've got mine wired up to my PID. I actually only use it during the mash as I don't need it during the boil. Works brilliantly, keeping power levels just right to maintain mash temps without scorching the wort.

 

[entertheflagon]

That's a good policy. I always go for a margin of 2x against any no-name stuff I get from China and I never buy brand-name components from there - too many fakes and resold QC rejects around.

Power ratings apart, check the construction and heatsinking.
Just picked up some of these SSR's for less than a tenth of what I paid for a branded Croydon type from RS.And that with a PID controller thrown in!
They look like toys in comparison so I'd be sure not to stress them.
There is a screw thread protruding from their flimsy base that will stop proper heat sink contact and could be a common cause of failure. Lap it smooth with the base ( which is not a substantial copper slab like a good SSR) and use thermal grease.
It looks like it's a single triac that does the business, not a pair of back to back thyristors I'd've expected.
Use them, and I will, but I'd be putting nowhere near their rated current through them and be warned, they often fail as short circuit, I'll sort a safety cut out for my own use.

 

[James Read]

Thanks Foxbat - built this yesterday and used on a brew. We also used it to control the water for Strike and Sparging - very handy!
I'm no master electrian, but I found the instructions well laid out and easy to follow.
I think the only issue was the cover to the power regulator wouldn't sit over the screws I used.

 

[foxbat]

Thanks Foxbat - built this yesterday and used on a brew. We also used it to control the water for Strike and Sparging - very handy!
I'm no master electrian, but I found the instructions well laid out and easy to follow.
I think the only issue was the cover to the power regulator wouldn't sit over the screws I used.

Glad it worked for you. I use mine every brewday for the whole length of the boil.

 

[Gerryjo]

Glad it worked for you. I use mine every brewday for the whole length of the boil.

Have only come across this thread today @foxbat and certainly plenty of detail.It's ironic as I had come across one on eBay a while back with a 4kw rating at under £6 thinking it was too good to be true.
I have now since converted a 20l tea urn to a heat exchanger so as to recirculate from the mash tun and actually incorperated this unit into the base ring of the boiler and certainly works a treat.https://www.thehomebrewforum.co.uk/threads/herms-set-up.82389/

 

[Markgee]

Thanks for posting this up. Just what I needed and I'll be giving this ago in the next couple of weeks

 

[foxbat]

Thanks for posting this up. Just what I needed and I'll be giving this ago in the next couple of weeks

I use mine every brew day during the boil. On my system, somewhere between 60% and 65% of a 2.4kW element is enough to get me a nice low-intensity boil.

 

[Markgee]

I want to use this on a 2.4kw element so that is good to know. Thanks again for taking the time to post this info up.

 

[cushyno]

Based on the prior art of @foxbat and @AdeDunn, my switchable PID and/or power regulator has been well worth the effort to build it. About 12 brews under its belt so far. Works great with a 2.4kw element.
Includes 12v transformer for pump and fan to keep things cool inside the box.

 

[kelper]

I had already read Foxbat's excellent thread on a SCR Variable Voltage Regulator. Initially, I did not want to modify the wiring on my brewer as it's under warranty. But it's a better engineering solution. I have ordered this one. https://www.ebay.co.uk/itm/173791600021

 

[johncrobinson]

An SCR controller will reduce the possible power drain. if power is such a problem use gas.
I suppose the real truth is that some members are finding their domestic supplies are not quite up to running a brewery.
God help us when Millions are plugging in there electric cars EVERY night.

 

[Paulchef]

Something for me to build in the future, so posting here as it’s easier to find next time

 

[TheOsprey]

Something for me to build in the future, so posting here as it’s easier to find next time

Most modern browsers use bookmarks...

Edited to add emoji and hopefully remove unintended snark.

 

[foxbat]

Something for me to build in the future, so posting here as it’s easier to find next time

2 years on and I'm still using mine on every brewday.

 

[The-Engineer-That-Brews]

Nice work there Andy @foxbat :-)
Glad to see I'm not the only person who's built themselves a power controller for their copper, after seeing vast quantities of wort boiling away into the atmosphere and the 'leccy meter spinning away like a '78... In fact I built a multipurpose box that I also use for temperature control of my mashing process, but that's a different story.
Back in the Dark Ages I did my degree in electronic engineering (with extra beer) so it was a good opportunity to dust off the old soldering iron and do a bit of practical design.
I took a slightly different route to Andy and based mine on an embedded controller (an arduino Nano clone) and a Solid State Relay 'SSR'. The controller detects the mains zero-crossings and fires the SSR into conduction for selected pattern of cycles in order to achieve the duty cycle you want. (Hardcore geeks may be interested to know it does this using a variant of the Bresenham algorithm).
I'm afraid I haven't got any very good photo's of it because I'm doing a bit of work on it at the moment, but here's a couple of shots.
IMPORTANT NOTE If you're building anything like this then be extremely skeptical of the power ratings of any SSR you buy off eBay or Amazon. Every single one of the SSRs I've been supplied from those sites has been a fake that uses under-specified triac components. They are fine for 'toy' projects controlling a light bulb, but would create a serious fire risk when controlling the significant load of a 2.4kW heating element. (see this article for details). My advice is to shell out an extra tenner and get a decent one from the likes of RS or Farnell etc. Yes, they are a bit more expensive but in my humble opinion it's worth it for the reduced level of risk.