British BBQ Society Forums

I have been reading with interest your ideas for a homegrown pit controller.
So, I have been rooting through the shed and come up with a 12v pid controller, a commercial oven thermistor(rated to 350 degrees C), a somewhat large centrifugal fan, but although it's only 31W, it's 240v. I also have a SSR, which will run the fan.

So I'll run all the 240v stuff off a small invertor, and only have one 12v dc supply. I have some big sealed lead acid batteries, so power is not a problem.

All this will go in a plywood box, which will sit at the side of the drum and connect to the uds with a flexible hose.
If it works it will be great, if not, well it's not been a loss.
I have run it up, connected by all sorts of bodge wiring on the bench, so it works as a going concern, it just needs sticking in a box and making pretty.

All we've got in our shed, other than stuff are some out of date seeds? Keep us updated and I'll try and understand what you are on about

Is there any wisdom on the best way to attach a fan?

Is it best to blow from the bottom or suck air fom he top? What about heat issues and plastic fan parts?

I've seen some UDS designs with piping - is that to give some distance between the fan and the heat source?

You are not wrong there Keith. Iam a serial squirrel, if it looks handy it gets tucked away. It's a shame, I haven't got a clue where stuff is.

@Aris, I would have thought that blowing air in is a lot less trouble than sucking it out. You blow cold air in, but suck hot air out, as you mentioned, it's going to play havoc with any component in its path.
Iam just going to push a plastic drain hose off the fan and straight onto one of the air vents. The plan is that I leave one of the other air vents just cracked, so some air can get in and not put out the fire. Then when a rise in temperature is needed, the controller brings in the fan, until a set temp is reached and cuts out again.
I imagine if it works, it will be a fire up and forget device, if not, well it keeps me out of trouble.

I'll take some piccys and keep you informed of how it goes, good or bad.

Please keep us up to date thanks. I just worry that any bits of plastic attached to the drum will melt.

aris wrote:Is there any wisdom on the best way to attach a fan?

Is it best to blow from the bottom or suck air fom he top? What about heat issues and plastic fan parts?

Suggest you read back up this thread a ways, and particularly this post

viewtopic.php?f=29&t=1690&start=30

where Steve explains what he has done with a fan and dog bowl.

You definitely want to blow from below.

Got some bits and pieces for the Arduino. Man, this is so fun it is not funny. Easy peasy to program too (and i'm not a professional programmer).



Pretty it isn't - but basically it has been configured to show the ambient temperature & humidity on the LCD screen, and also the distance between the ultrasonic sensor and whatever it is pointing to. If anything comes within 20cm of the sensor, it activates the buzzer, and also switches on a relay (which apparently can handle 250VAC/10A)

Not particularly useful for a BBQ - but a nice proof of concept. Now to get some thermocouples hooked in here - now we're talking!

aris wrote:Got some bits and pieces for the Arduino. Man, this is so fun it is not funny. Easy peasy to program too (and i'm not a professional programmer).



Pretty it isn't - but basically it has been configured to show the ambient temperature & humidity on the LCD screen, and also the distance between the ultrasonic sensor and whatever it is pointing to. If anything comes within 20cm of the sensor, it activates the buzzer, and also switches on a relay (which apparently can handle 250VAC/10A)

Not particularly useful for a BBQ - but a nice proof of concept. Now to get some thermocouples hooked in here - now we're talking!

Don't ever attempt to take that on a plane, things could get messy

Davy wrote:

aris wrote:Got some bits and pieces for the Arduino. Man, this is so fun it is not funny. Easy peasy to program too (and i'm not a professional programmer).



Pretty it isn't - but basically it has been configured to show the ambient temperature & humidity on the LCD screen, and also the distance between the ultrasonic sensor and whatever it is pointing to. If anything comes within 20cm of the sensor, it activates the buzzer, and also switches on a relay (which apparently can handle 250VAC/10A)

Not particularly useful for a BBQ - but a nice proof of concept. Now to get some thermocouples hooked in here - now we're talking!

Don't ever attempt to take that on a plane, things could get messy

Heh yes. In a similar vein, the things you can (simpy) do with the Arduino if you have evil intentions do not bare contemplating.

I've ordered one of these - might work out well with the Arduino pit controller.

http://dx.com/p/outdoor-bbq-barbecue-fa ... -aa-133046

I'll stick this at the end of a long pipe to keep it cool, and wire up the power switch to an arduino relay to switch it on and off. At the price, it's worth a punt.