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JackH
OfflineAdmin
· 05/27/2020 3:01 PM
Does it happen with all threads or certain one?

pisanoal
Offline
· 05/27/2020 10:14 AM
Anyone else have issues seeing the whole window of a thread when accessing from a mobile phone? Any fixes?

allenb
OfflineAdmin
· 04/02/2020 4:50 AM
Morning Ed, I haven't done any green coffee hoarding yet but am hoping the supplies don't end up like the toilet paper isles!

snwcmpr
Offline
· 03/31/2020 2:53 PM
Hey Ed. Thanks. roar

homeroaster
Offline
· 03/31/2020 11:21 AM
Hey quarantined home roasters! I hope you have great coffee! If they have a run on coffee, I hope you're set with your great home roast! Find me on Facebook! Ed Needham

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TC4+ Arduino coffee roaster shield (TC4-compatible)
renatoa
As I see engraved on the PCB, you have there a 16 Amps triac, so heatsink is the real limit.
Even current paths on the PCB aren't a real issue, if you double the PCB tracks with some AWG18 wire.
If the traces are 3 mm width, they are good for 12 Amps. They will heat up though, but at the limits of skin touch, 50-60C.
 
mtbizzle
Hey all Grin

Anyone used the TC4+ w/ a Nostalgia popper?

I've been reading up, trying to decide on a plan for turning my Nostalgia popper into an Arduino/Artisan/PID controlled mini-roaster. As intended MG512's TC4+ seems very appealing to someone like me, with minimal experience soldering and coding. This may be my best shot at copying a winning recipe ThumbsUp

Trying to settle on a plan, determine shopping list, and get everything ordered.

If someone could 'audit' my shopping list, that would be greatly appreciated!

W.I.P. Shopping List
  1. Unassembled tc4+ kit & Arduino Uno - ($74) - from the man himself, MG512
  2. Fotek SSR-40DA - ($9.50) - Amazon
  3. Plain tip k type thermocouple for ET - ($6) - from Amazon - https://www.amazon.com/0-400C-Tempera...0776PY1NW/
  4. BokWin brand flexible tip k-type thermocouple - ($7) - 1mmx100mm probe w/ 1.5m cable
  5. IIC 20x4 LCD display - ($13) - Amazon - https://www.amazon.com/SunFounder-Ser...UMP9C?th=1
  6. HC-05 Bluetooth transceiver ($8) - Amazon - https://www.amazon.com/dp/B071YJG8DR/...HX2VB334OC
  7. Spade terminal connector kit - ($10) - Amazon
  8. Kapton (heat) tape - ($6) - Amazon
  9. Enclosure - any advice on an enclosure for all this? What have others done?
  10. Any addtl wires needed?

HAVE: Soldering equip, drill, Nostalgia popper.
Can get a Poppery 2 for <$35, if it would serve as a better popper to mod.

Looks like that comes to roughly $150, or $185 if I use a Poppery 2.

Some Questions
Re. #1 - TC4+ & Uno - just requires through hole soldering, right?

Re. #4 - the thermocouple - I assume 1mm diameter and length are fine. Probe appears flexible, wire appears shielded? images-na.ssl-images-amazon.com/images/I/5106EHFX2xL._AC_SL1000_.jpg ...

Or I can get same probe MG512 used for $16 - https://www.overstock.com/Home-Garden...duct.html?. If anyone has advice on thermocouples, I'm all ears!

Re. #5 - IIC 20x4 LCD - Functionally equivalent to one used by MG512? Does not seem to have any wiring included. Is there some standard 4 pin connector that would allow wiring from this to the TC4+?

Re. #6 - HC-05 Bluetooth transceiver - Functionally equivalent to one used by MG512 (his are OOS)? This is a no-solder connection to the TC4+, right?

Re. #7 - spade terminal connectors - Are ring terminal connectors needed for the ground wires, or could I stick to only Spade terminal connectors? By the looks of things, this build would only require through hole soldering and terminal connectors like this -- is that right?

Regarding fan & PSU. If anyone else has used MG512's setup paired with a Nostalgia popper, could you advise on how you handled the fan/PSU situation? A sticker seems to say '18v' (see attached image), so I'm assuming DC. Another user said the Nostalgia has a fan driven by a low voltage brush motor driven via a secondary heater coil.I have a 19v 7.1a laptop charger. MG512's guide suggests that slightly higher voltage could work. Obviously, not taking chances or guesses with these sorts of details. Could anyone advise?

Also -- MG512 -- did you ever get around to integrating Wi-Fi? Saw you mention this. Wondering as I'd either need (a) Wi-Fi/Bluetooth connection to PC or Android, or (b) buy a laptop just for Artisan! thumbdown

Thanks all, & esp. MG512 - this is a wonderful resource for humble poppers!
mtbizzle attached the following image:
img_20200423_142248_1.jpg

Edited by mtbizzle on 04/25/2020 6:39 PM
 
mg512

Quote

mtbizzle wrote:

Hey all Grin

Anyone used the TC4+ w/ a Nostalgia popper?

I've been reading up, trying to decide on a plan for turning my Nostalgia popper into an Arduino/Artisan/PID controlled mini-roaster. As intended MG512's TC4+ seems very appealing to someone like me, with minimal experience soldering and coding. This may be my best shot at copying a winning recipe ThumbsUp

Trying to settle on a plan, determine shopping list, and get everything ordered.

If someone could 'audit' my shopping list, that would be greatly appreciated!

W.I.P. Shopping List
  1. Unassembled tc4+ kit & Arduino Uno - ($74) - from the man himself, MG512
  2. Fotek SSR-40DA - ($9.50) - Amazon
  3. Plain tip k type thermocouple for ET - ($6) - from Amazon - https://www.amazon.com/0-400C-Tempera...0776PY1NW/
  4. BokWin brand flexible tip k-type thermocouple - ($7) - 1mmx100mm probe w/ 1.5m cable
  5. IIC 20x4 LCD display - ($13) - Amazon - https://www.amazon.com/SunFounder-Ser...UMP9C?th=1
  6. HC-05 Bluetooth transceiver ($8) - Amazon - https://www.amazon.com/dp/B071YJG8DR/...HX2VB334OC
  7. Spade terminal connector kit - ($10) - Amazon
  8. Kapton (heat) tape - ($6) - Amazon
  9. Enclosure - any advice on an enclosure for all this? What have others done?
  10. Any addtl wires needed?

HAVE: Soldering equip, drill, Nostalgia popper.
Can get a Poppery 2 for <$35, if it would serve as a better popper to mod.

Looks like that comes to roughly $150, or $185 if I use a Poppery 2.

Some Questions
Re. #1 - TC4+ & Uno - just requires through hole soldering, right?

Re. #4 - the thermocouple - I assume 1mm diameter and length are fine. Probe appears flexible, wire appears shielded? images-na.ssl-images-amazon.com/images/I/5106EHFX2xL._AC_SL1000_.jpg ...

Or I can get same probe MG512 used for $16 - https://www.overstock.com/Home-Garden...duct.html?. If anyone has advice on thermocouples, I'm all ears!

Re. #5 - IIC 20x4 LCD - Functionally equivalent to one used by MG512? Does not seem to have any wiring included. Is there some standard 4 pin connector that would allow wiring from this to the TC4+?

Re. #6 - HC-05 Bluetooth transceiver - Functionally equivalent to one used by MG512 (his are OOS)? This is a no-solder connection to the TC4+, right?

Re. #7 - spade terminal connectors - Are ring terminal connectors needed for the ground wires, or could I stick to only Spade terminal connectors? By the looks of things, this build would only require through hole soldering and terminal connectors like this -- is that right?

Regarding fan & PSU. If anyone else has used MG512's setup paired with a Nostalgia popper, could you advise on how you handled the fan/PSU situation? A sticker seems to say '18v' (see attached image), so I'm assuming DC. Another user said the Nostalgia has a fan driven by a low voltage brush motor driven via a secondary heater coil.I have a 19v 7.1a laptop charger. MG512's guide suggests that slightly higher voltage could work. Obviously, not taking chances or guesses with these sorts of details. Could anyone advise?

Also -- MG512 -- did you ever get around to integrating Wi-Fi? Saw you mention this. Wondering as I'd either need (a) Wi-Fi/Bluetooth connection to PC or Android, or (b) buy a laptop just for Artisan! thumbdown

Thanks all, & esp. MG512 - this is a wonderful resource for humble poppers!


1: Yes, only through-hole!

4: Should be fine I imagine, admittedly I'm not an expert on thermocouples though. ;)

5: Looks like it should be compatible. For wiring, you want female-female Dupont cables, usually sold in strips of 20 or 40 wires that you can peel apart. (You need 4 for the display).

6: Yes, should be equivalent. Configuration can be a bit of a pain, as there are dozens of different firmware variants out there with slightly different default baud rates and command sets.

7: I used ring connectors for earth because they can't slip out, but that might be overly safety-conscious of me. (I'm not an electrician and don't know your local regulations, so check with someone qualified and certified to be sure.) Yes, mostly through-hole soldering, crimping connectors, and drilling a hole for the TC (! - you do need a drill!). Also some basic Arduino flashing, unless you get the pre-configured Arduino.

I don't know the Nostalgia popper, and can't tell from the image. Are there diodes or a PCB anywhere in the roaster?

For Wi-Fi I've once used a pair of NodeMCUs to create a Serial to WiFi to Serial bridge - not the most elegant solution, but requires no changes to either the roaster hard- and firmware, or the host computer. I never got around to publishing this, but I can email you the sketch I used if this is of interest.
 
https://www.tindie.com/products/15798/
mtbizzle
Thanks for the reply, MG512

Trying to sort out as much as I can in advance, in hopes I can minimize delays later on. Only have a 10 day window where I can work a lot on this!

Quote

[bluetooth] configuration can be a bit of a pain, as there are dozens of different firmware variants out there with slightly different default baud rates and command sets.


I'm reading that the default baud rate for the module I linked is 9600. Is there any other information I could look up that would help with configuring the bluetooth module - commands, firmware, baud, etc? (don't know what you don't know).

Quote

Are there diodes or a PCB anywhere in the roaster?
Yes I believe so - see image attached. There is a sticker just above this that says '18v' but it's not entirely obvious what it's referring to.

Edit: image file upload wouldn't work -- see image link here -- https://i.imgur.com/vrEDfdh.jpg

Quote

For Wi-Fi I've once used a pair of NodeMCUs


OK, so some additional parts for WiFi.

Somehow I'm just now realizing that there is no Artisan for android. I do not have a laptop so was hoping to connect via my android phone. Is there a way to connect this TC4+ setup to android that allows for PID control and functionality like Artisan?? I heard @greencardigan has some Android app, but I have not been able to find any details on this.

What a bummer! Not sure if the plan will work without a laptop or an android app.
Edited by mtbizzle on 04/27/2020 3:28 PM
 
renatoa
Also, don't forget there is BT and... the new BLE !
Beware to not buy a wrong adapter, i.e. BLE, which don't work with hardware older than 3-4 years.
btw, greencardican app don't work with BLE ;)

For some of the reasons you exposed above, and others, I forked and expanded TC4 using ESP instead Arduino, to levels that many can't even dream.
I don't have onscreen graph, but I don't need it, it's only a fancy gimmick. I didn't used the graph to guide me even in the times when I experienced tethered roast with Artisan.
Instead, I have the most useful feature of Artisan graph: the trending lines, i.e. real time prediction of roasting milestones: dry end and FC. Much more useful numbers to control the roast, instead a profile.
Also, I am saving internally the whole roasting progress, and you can DUMP (yeah, a new command) the saved data, in Artisan csv file format, ready to import into Artisan and analyse later, or, just for the record.
The need for a computer for me is now really gone.
For these reasons, I don't get it why this insistence to keep using these dinosaur boards of Atmel family, with the memory limitations not allowing adding any new ideas and further improvement of TC4 software. An equivalent ESP board is 3x cheaper and 10 times more powerful, it is not the future, but the first choice of every new design for some years.

Disclaimer: the rant above is not a bash against the boards subject of this thread, nor their author, but the platform they are mounted onto. Grin
 
JackH
Is BLE another acronym we must figure out?
---Jack

KKTO Roaster.
 
renatoa
https://en.wikipedia.org/wiki/Bluetoo...Low_Energy
 
mg512

Quote

mtbizzle wrote:

Thanks for the reply, MG512

Trying to sort out as much as I can in advance, in hopes I can minimize delays later on. Only have a 10 day window where I can work a lot on this!

Quote

[bluetooth] configuration can be a bit of a pain, as there are dozens of different firmware variants out there with slightly different default baud rates and command sets.


I'm reading that the default baud rate for the module I linked is 9600. Is there any other information I could look up that would help with configuring the bluetooth module - commands, firmware, baud, etc? (don't know what you don't know).

Quote

Are there diodes or a PCB anywhere in the roaster?
Yes I believe so - see image attached. There is a sticker just above this that says '18v' but it's not entirely obvious what it's referring to.

Quote

For Wi-Fi I've once used a pair of NodeMCUs


OK, so some additional parts for WiFi.

Somehow I'm just now realizing that there is no Artisan for android. I do not have a laptop so was hoping to connect via my android phone. Is there a way to connect this TC4+ setup to android that allows for PID control and functionality like Artisan?? I heard @greencardigan has some Android app, but I have not been able to find any details on this.

What a bummer! Not sure if the plan will work without a laptop or an android app.


Some modules have a separate "configuration mode", which is often using a different baud rate than normal operation. I've seen 38400 with no newline, for instance. On those modules you also often have to hold down one of the buttons on the module as you power it up, to enter that mode. Other modules I've seen don't have that. Once you're in AT / configuration mode, the commands are usually similar, but not always exactly the same, e.g. sometimes it's "AT+PIN1234", sometimes "AT+PSWD1234", etc. Just takes some trial and error. I do offer preconfigured bluetooth modules if you don't want to have to deal with this. But it is usually easy to figure out. Sometimes the modules come with a manual, too, but not always.

I can't see a picture attached to your last post. On the previous one I couldn't see any diodes.

As renatoa mentions, there is or at one point was an Android app, but I've never used it myself, and I don't know how well maintained it is these days. Artisan is definitely the more common setup. Do you not have a PC at all?

Quote

JackH wrote:

Is BLE another acronym we must figure out?


Bluetooth Low Energy is another name for Bluetooth 4.0. Contrary to what its name suggest it is not very compatible with previous Bluetooth. In particular, it doesn't have a simple Serial protocol. There are modules for it in a similar form factor, I think HC-08. I've played around with one once, but it was not worth the effort. HC-05 should always be regular (non-BLE) Bluetooth though, so should always work.
 
https://www.tindie.com/products/15798/
mtbizzle
MG512 --

Quote

I can't see a picture attached... I couldn't see any diodes.


Sorry about that - img wouldn't upload. Here you go --
https://i.imgur.com/vrEDfdh.jpg

I think the biggest "?" for me now is the fan electronics. Not sure what I need to do re. the 'flyback diode' mentioned in Instructable.

When it comes to PSU for the popper's fan, of course have to get the details right. Instructable says 'aim for at least twice the rated power' of the fan. So the steps would be(?): 1. measure fan w/ voltmeter while has been running a bit. 2. PSU should match voltage, or +1 voltage, and should approx. double amperage? (Sound right?)

There is an '18v' sticker near the fan. Another user with the same popper told me:
"I found some measurements I made: 12v slow, 16v fast, 325mA at slow speed: So 18v is right, power supply should be approx 20v at 500mA - 1 amp capacity."

I have a laptop charger, 19v 7.1a. Too much power??

Quote

Artisan is definitely the more common setup. Do you not have a PC at all?


(Edit:) Just tried out an adroid app called Chome remote desktop. Seems to work very well - casts screen and allows clicks etc pretty seamlessly. I figure I could do BT -> PC, artisan on PC -> phone via chrome remote desktop. Open to any ideas here.

Quote

Just takes some trial and error. I do offer preconfigured bluetooth modules if you don't want to have to deal with this. But it is usually easy to figure out


Sounds good. If there are only a few known places where issues tend to arise, I think I'll give configuring it a shot -- just trying to cut costs. Should be an opportunity to learn a bit.

From the HC05 module documentation --

Quote

8. After pairing succeeds, can be used as full duplex serial port. No need to understand any Bluetooth
protocol, but only support 8-bit data bits, 1-bit stop bits, no parity communication format. This is also
the most commonly used communication format, does not support other formats!

9. Press the key and then power up the Bluetooth module to enter at mode, set parameters and
query information
10. Can switch host and machine mode from at command


The bold bit doesn't pose any problem does it?

If I successfully complete this, I'll be sure to take lots of notes and pictures to share for anyone else that ends up in my position!
Edited by mtbizzle on 04/29/2020 12:48 PM
 
JackH
Thanks mg512! Never heard of it.

Just trying to make it easier for other members to understand. Not all of us are engineering types.
I have always disliked acronyms.
---Jack

KKTO Roaster.
 
mtbizzle
Hey Renatoa, I'm personally leaning towards MG512's TC4+ setup because it seems to me to be the way to get to PID/temp monitoring/temp control, with the least room for error, as a someone inexperienced with pretty much all areas of this project draws on. E.g. soldering/electrical, issues related to getting bad chips or chips that work slightly differently than the original design, any software issues. I see it as a way of getting as close as I can to a fully compatible hardware/software bundle with less room for error / need for troubleshooting by someone experienced (ie, not me!). Even guides/schematics can be difficult to interpret/understand for someone who doesn't have any background in this and doesn't know the vast majority of the lingo.

Quote

Also, I am saving internally the whole roasting progress, and you can DUMP (yeah, a new command) the saved data, in Artisan csv file format, ready to import into Artisan and analyse later, or, just for the record.
The need for a computer for me is now really gone.


The cost issue and the lack of need for a computer are certainly attractive features for me. So, with your setup, do you load a profile to the board somehow, monitor values on the LCD, and then export the saved data later (if desired)? I don't entirely grasp how it all works. For example, how do you start a roast, choose a profile, etc? Also, your github mentions connection to android via wifi with a HT-06. What app is that -- greencardian's? (Still trying to get a clear picture of how it all works, from the user's end!)

Would you disagree about my judgment about ease of configuration/minimizing room for error/problems? Appreciate everyone's help and thoughts -- you all are my guides here!

Quote

For these reasons, I don't get it why this insistence to keep using these dinosaur boards


No need to word it like that! Just trying to find the best way to this destination for me. I'm sure if I had a lot of experience, I would've already done something different by now.
Edited by mtbizzle on 04/28/2020 1:41 AM
 
renatoa
Please, keep my wording with all the salt you need to make it sweeter Grin
I am not an English speaker, and also a latin-slavic combination, known for the passion of what they believe.

Regarding this part of your post:

Quote

it seems to me to be the way to get to PID/temp monitoring/temp control, with the least room for error

...
please do understand that my solution can run exactly the same 100% TC4 code, if desired, but would be a shame to limit it that way.
The reason I developed it is because I found the original not good enough for my pickiness, especially PID and reading errors part.
I am pretty sure that many parts of my development could replace TC4 code and make it better, but the limited memory of Arduino board don't allow this.

Quote

as a someone inexperienced with pretty much all areas of this project draws on.

... this is the part where you have right sadly... maybe is time to polish my experimental project into a more streamlined concept.
Edited by renatoa on 04/28/2020 3:54 AM
 
mtbizzle

Quote

with the least room for error


I should have clarified - I meant the project that has less room for error, in setup, when trying to assemble, configure, troubleshoot. Maybe I am overthinking this, but my guess is that there are a lot of small ways this sort of project can run into problems during setup/assembly/configuration. If the issue was not obvious, I would probably have difficulty trying to troubleshoot. So, I guess you could say, I'm seeking a build that balances features, cost, and ease of setup.
 
mtbizzle
Small update Grin

One of the issues I was trying to reason through was access to Artisan or similar, without a PC right next to me. I mentioned that chrome remote desktop (cast and control PC from phone) seemed to work well. Did a little test run (not my roast) --

i.imgur.com/fXJ1X1v.png

Looks great! My phone screen is 6.2in x 3in, the details are visible enough.

Only potential issue, I think, would be hitting the buttons. Thankfully, it seems Artisan allows adjustment of buttons size - large should make that easier. ThumbsUp Seems like a very easy option if anyone faces a similar problem in the future.

Switching gears -- I want to go ahead and purchase parts so I can get started here soon.

First, could someone help me determine the appropriate PSU for the fan? (Have multimeter).

Second, I know I will have questions when I try to assemble & configure. Given the whole coronavirus scheduling, there is a nice window of a few days where I can devote a lot of time to this, but after that window passes, not so much. This is a funny "?" to ask -- do you all think I could get technical help with relatively quick turnaround for troubleshooting assembly/configuration by posting here? Hope that isn't taken the wrong way! Just trying to get a sense of whether I could complete this in the timeframe I have!
Roast: Nostalgia popper
Grind: Comandante c40, Encore
Brew: v60, flair espresso, moka pot, french press, cezve w/ 'Scott Rao' water
Ask me about Tea!
 
mg512
PSU voltage should match the fan's rated voltage, or maybe a little bit higher (at your own risk). Amperage I would try to exceed the fan's rated amperage by a good margin, as startup current is often a lot higher than steady-state current. For my own setup, I use somewhere between 2 and 3 times the steady-state current.

Hm, I suppose you have seen how quickly people tend to reply on here? Also, many questions have already been answered somewhere on here, or elsewhere on the internet, or at least you might be able to piece together the answer from information available online. (And often that's half the fun!)

Generally, best case, you can probably do this in a day. Worst case, something breaks and you need to wait until you get a replacement, or you spend a day trying to figure out why something isn't working. If you just want to (or worse, need to) be able to roast coffee, and it's very time critical, there is a risk. On the other hand, if you're here (also) because you enjoy tinkering with technology, you will definitely be able to spend a few days doing fun stuff with this.
 
https://www.tindie.com/products/15798/
mtbizzle
ThumbsUp

USB connects via the Arduino Uno -- right? So I would need a USB type B connector?

Also, re. perforated sheet you used inside the enclosure for securing & grounding/earthing. Did you screw the sheet to the enclosure, and then screw all electronics to the sheet? Feel like I must be missing something. Is the TC4+/Arduino really in contact with that metal sheet?

My instinct would be to use standoffs to secure things, but not sure I can use those to secure the Arduino/TC4+ because the TC4 is stacked ontop of the Arduino.
Edited by mtbizzle on 04/30/2020 9:15 PM
Roast: Nostalgia popper
Grind: Comandante c40, Encore
Brew: v60, flair espresso, moka pot, french press, cezve w/ 'Scott Rao' water
Ask me about Tea!
 
mg512
Yes, USB type B. Most Arduinos include a suitable USB cable, usually a pretty short one though.

I use the perforated sheet for earthing things. In the guide, the Arduino is indeed secured with standoffs! Not in (electrical) contact with it. I attached standoffs to the Arduino, then stacked the TC4+ on top, then secured the standoffs to the sheet. The sheet isn't strictly necessary of course, there are other ways of mounting thigns.
 
https://www.tindie.com/products/15798/
mtbizzle
Apologies for the uninteresting questions here... If I am testing the power rating of the popper fan, where do I put the multimeter + & - ?

Measure "V" and "A" on multimeter after fan runs for a few seconds, correct?

https://imgur.com/a/ckJtnUP

Also I'm curious. What are people's thoughts on higher wattage roasters, like the 1200 and 1500 watt poppery's, for mods like the TC4+?
Edited by mtbizzle on 05/05/2020 5:34 PM
Roast: Nostalgia popper
Grind: Comandante c40, Encore
Brew: v60, flair espresso, moka pot, french press, cezve w/ 'Scott Rao' water
Ask me about Tea!
 
mg512
Voltage you would measure in parallel, current in series with the motor. You already know the (rough) voltage, as it's printed on the motor. ;) Current you don't strictly need to measure either - I never did on mine, as I didn't want to mess with measuring on something that was plugged in to mains. You could instead measure resistance of the heating coils and motor and calculate current from that. Or there might be a model number printed on the fan, and you might be able to google it. Or, you just trust that it will be of a similar magnitude as all the other popcorn machines out there, and just budget aboug 2A steady state current. If you overvolt the fan, the current will change anyway, so measuring it at stock voltage gives you a rought lower estimate at best anyway. And you need to overspec the power supply anyway, as start-up current is much higher, and not as easily measured. Bottom line, get a 5A PSU, and most likely it will be fine. Worst case, you might have to stagger the fan startup, i.e. go from 0% to 50% and then to 100%, instead of jumping directly to 100%, to lessen the startup current.

The machine I used is rated at 1200W, and that has always been plenty. Bear in mind that with the dual-heating-coils-as-voltage-divider-for-DC-fan type machines, if you end up driving the primary heating coil directly from mains as in the guide, that will also significantly up the wattage it draws! Even more so on 120V than on 240V, as the 18V extra is a larger relative increase. This too is something I wouldn't worry about, unless it actually turned out to be an issue, because 99% of the time it won't.
 
https://www.tindie.com/products/15798/
mtbizzle
I have the popper disassembled, intending to try to measure voltage and amperage of the fan for making a call on a fan PSU, based on what you said I guess I shouldn't do so.

I know in your guide, you say,

Quote

I measured the resistance of the motor and both heating coils


If I should do this, v.s. going with the '18v' sticker to use my 19v7.1 PSU, can someone point me to where I would put the multimeter red/blk to measure this? I also don't know how to use this ohms measurement to calculate the values I'm looking for.

i.imgur.com/WVVXAbr.jpg

Quote

mg512 wrote:
... you need to overspec the power supply anyway, as start-up current is much higher, and not as easily measured. Bottom line, get a 5A PSU, and most likely it will be fine....

... if you end up driving the primary heating coil directly from mains as in the guide, that will also significantly up the wattage it draws! ...This too is something I wouldn't worry about


I have a 19v 7.1a laptop charger that I am hoping to use for this purpose, but of course only if it is appropriate. The unit just attached to the diodes in the picture above (fan & motor to my understanding) has a sticker '18v'.

So 19v would be a slight overvoltage but indications seem to be that won't be a problem.

What about amps? 7.1a. Just want to be sure, mains electrical and all.

i.imgur.com/PmHcmRm.jpg

Once I settle this PSU matter, will be moving forward with the build Grin
Edited by mtbizzle on 05/18/2020 1:31 PM
Roast: Nostalgia popper
Grind: Comandante c40, Encore
Brew: v60, flair espresso, moka pot, french press, cezve w/ 'Scott Rao' water
Ask me about Tea!
 
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