Alternative popper mod suggestions

[Dimal]

Re: Alternative popper mod suggestions

plug packs are switch mode 12V DC 2A

Even worse...

You cant combine these safely mate. Just grab a suitably rated single PSU and youre laughing... If you allowed for a 30VA load that would cover it.

Mal.

[Firepower]

Re: Alternative popper mod suggestions

Ok will try single power supply, thank for advice.

[emckissock]

Re: Alternative popper mod suggestions

Another tip for sourcing power supplies - some ducted heating systems have a suitably rated 24v transformer.
Ours died last week (bung triac which then vapourised a couple of resistors). While trawling the web for parts, I noticed transformers for the controllers were 24v and cheaper than jaycar. Also, these are the sort of things that often get scrapped rather than repaired.
Just thought Id mention it.

[Pete39]

Re: Alternative popper mod suggestions

Ive been working on moding a Kmart popper too. Im using a Xmas tree light Xformer (24VAC, 36VA) which works quite nicely on the numbers. It sits at about 21 VAC into the rectifier (CF MALs 20V above) and the motor is running at almost spot on 18V DC. I was hoping for a little bit more to help when the beans are still heavy but am going to try with the current set-up first.

Nice biscuit tin WM

[emckissock]

Re: Alternative popper mod suggestions

Pete39 - I find with the 28v ac supply, my fan at full power can just manage to agitate 150g of beans without assistance from cold and progressively less power as the roast progresses, you may need to use smaller batch, or stir for the first few mins. I am very happy with the split fan and heat control - my second attempt at following a defined profile was within 5 degrees throughout the roast, with only minor adjustments needed at each stage - start with full fan, 650W power, gradually increase power as beans heat, then gradually decrease fan as they get lighter. Im running full heat and about 50% fan from about 10mins, with a slight power drop just before I hit first crack.
While it would be possible to cool in the popper, my custom bean cooler is much faster. If you do intend to cool in the popper, youll need a mesh lid for the chimney as full fan at the end will blow beans all over the place.

[Pete39]

Re: Alternative popper mod suggestions

Thanks for the info WM - based on that I think Ill start digging for a bit more juice on the fan, was hoping for a batch closer to 200g. Have a blower/vac doing nothing  ;D Glad yours is going well.

[Firepower]

Re: Alternative popper mod suggestions

I wonder if mounting the popper chamber on a heat gun would allow variable temp and fan speed of the heat gun to control roasting.

[Dimal]

Re: Alternative popper mod suggestions

Thanks for the info WM - based on that I think Ill start digging for a bit more juice on the fan, was hoping for a batch closer to 200g. Have a blower/vac doing nothing  ;D Glad yours is going well.

Bloody ell Pete...

That would send your popper way beyond Frankenpopper territory, more like Godzilla.... ;D ;D

Mal.

[emckissock]

Re: Alternative popper mod suggestions

FP, yep may work, but by that point you are no longer running a popper, but creating a whole new roaster (which may be well worth pursuing).

Another thought that occurred to me is that the limiting factor on popper batch size is the heat output of the standard element.
We can always restrict/recycle some/all of the exhaust air, but run the risk of cooking the cool side components.
Another option would be to take two poppers and either run a double barrell roaster off one control circuit with matched loads in each barrell, or take the two heating elements, put in series and either stir initially, or use a forced air input, such as a vac motor.

My recent foray into ducted heating repair also got me thinking about home roaster possibilities. Definitely not for a popper thread though...

[Pete39]

Re: Alternative popper mod suggestions

Thanks for the info WM - based on that I think Ill start digging for a bit more juice on the fan, was hoping for a batch closer to 200g. Have a blower/vac doing nothing  ;D Glad yours is going well.

Bloody ell Pete...

That would send your popper way beyond Frankenpopper territory, more like Godzilla.... ;D ;D

Mal.

Yeah, sounded exciting didnt it?? Sorry to disappoint, but have managed to get hold of a 30V transformer. Still have visions of a 500 mm-or-so tall glass tube with coffee beans happily dancing ... Maybe once I get this one going and get a bit of experience 

[emckissock]

Re: Alternative popper mod suggestions

Just thought it would be worth mentioning that anyone planning on driving the popper motor with higher voltage than specifications should check the rating on the rectifier diodes, or use an external rectifier. The aroma of burnt diodes would not enhance your roast.