Earlier in the blog I posted photos showing the circuit boards inside the roaster that were labeled 1000W.\u00a0 The roaster was reported as being 1500W and it’s a pretty major deal to be 1000W vs 1500W.\u00a0 After looking back at the blog and some of the things I’ve worked with and struggled it made me wonder more about the wattages used by the SR500.\u00a0 Additionally it seems there are a lot of people that come to this blog looking for information about how many watts the SR500 is.<\/p>\n
In the interest of providing accurate information I went out and got a device for measuring wattage drawn by a device.\u00a0 Upon plugging it in I discovered that the SR500 draws .8 Watts in “idle” mode.\u00a0 For comparison a coffee pot I had here with only an Off\/Timer\/On toggle button and a button to let you change the clock and a tiny little LCD you can’t even REALLY see except when trying to look at it to program the start brew time was drawing 1.2-1.5 watts.\u00a0 When I turned on\u00a0 the coffee pot it went to around 1460-1470 watts.<\/p>\n
Back to the coffee roaster the manufacturer reported it as 1500watts.\u00a0 Looking at the circuit board it seemed to show 1000W on one of the labels.\u00a0 Turns out it is indeed 1500 watts when running full force as described.\u00a0 I have no idea why the circuit board reports 1000 watts.\u00a0 I started thinking maybe there is something with the electronics and mainly the fan that would suck up a significant amount of wattage while it was turned on.\u00a0 Knowing the model of processor inside the circuit and the other parts there was not a lot of electric being consumed.\u00a0 This was proven when looking at the cool cycle.\u00a0 First let’s start with the typical roast numbers.<\/p>\n
Starting we have .8 Watts\u00a0 in a sort of standby mode waiting for the controls to turn the roast on. [Edit 4\/14\/11 – The meter in a sort of standby of its own with nothing plugged into it runs about .5 watts.\u00a0 This means the roaster in standby probably consumes something more like .3 watts.]\u00a0 Once I turned on power it lurched upward and for many of the settings hovered +\/-\u00a0 one to five watts one way or the other from the following numbers:<\/p>\n
Fan \/ Heat \/ Wattage Reported<\/p>\n
Low \/ Low \/ 1420
\nMed \/ Low \/ 1475
\nHigh \/ Low \/ 1500
\nLow \/ Med \/ 1420
\nMed \/ Med \/ 1475
\nHigh \/ Med \/ 1508
\nLow \/ High \/ 1420
\nMed \/ High \/ 1475
\nHigh \/ High \/ 1505 to 1520<\/p>\n
The wattages slowly ticked up and down without seeming to be connected too heavily to anything in particular that was going on.\u00a0 This was measured WITHOUT the roasting chamber in place allowing the roaster to simply run full force.\u00a0 When I have more time I’ll run a regular roast through and see if there is any significant peak points where the numbers differ much fluctuating during the roast and if there is a pattern to any of it.\u00a0 This leads to cooling.<\/p>\n
Cooling for all intents and purposes is the roaster running with all electronics EXCEPT for the heater.\u00a0 This is particularly interesting because the amounts that the wattage changes is not necessarily reflected on each of the tiers for the fan\/heater combo.<\/p>\n
High Fan \/ Cool \/ 182 watts
\nMed Fan \/ Cool \/ 148 watts
\nLow Fan \/ Cool \/ 107 watts<\/p>\n
As you can see the wattage of the roaster is pretty reasonable to be called 1500 watts.\u00a0 You cannot say that the HEATER is 1500 watts….\u00a0 but it IS a 1500+ watt device like most other items advertised that way.\u00a0 Why the internal parts are labeled 1000w I cannot imagine.\u00a0 My guess is there may have been an earlier design that reused the same circuit board to control things and it just needed a stronger heater element.<\/p>\n
The roaster appears to not vary the heat outside of the full power to the heater element and then it turns off when the LOW\/MED\/HI threshold is met.\u00a0 I expect to see the wattage go from 1400-1500ish down to the 140-180 range every time the heater cycles the way this looks.<\/p>\n
For those looking for an update on SD memory I am pleased to say that I found the problems with the SD memory wiring that were actually conflicting with more pins than I knew.\u00a0 I also found a couple other places that were conflicting randomly that I had odd symptoms that I had not traced yet.\u00a0 How did I do this?\u00a0 I blew up the datasheet pin diagram from 8.5 x 11 to 3 feet by around 2 feet something after color coding a few of the pin types and then systematically crossing out a few pins that I have no control over which ones are used because they either HAVE TO be used due to existing circuit boards on the development kit or else there are so many other pins being used in a “set” that I cannot use that function.\u00a0 Examples would be if you needed to use UART1 TX\/RX.\u00a0 These are on pins RF2 and RF8.\u00a0 ALSO living on these pins are SDI and SDO #3.\u00a0 Obviously if you use UART 1 those pins are tied up and now you cannot use SPI (SDI\/SDO) set number 3.<\/p>\n
Once I cross those functions off the list it makes it soooo much easier to find all the other functions that I need to place or can place in other locations.\u00a0 I’m gradually transferring these items into a schematic building power supplies and VGA interfaces etc onto them.\u00a0 I’m beginning to get closer and closer to having created a full schematic for the entire project up to this point.\u00a0 I can convert that schematic into a circuit board layout and after a few more rounds of tests and seeing if I can figure out a few more sensors I’ll probably be ready to test out a preliminary test board that will become a “condensed” development platform.\u00a0 This will let me test 1) building circuit boards, 2) knowing that I’m close to getting a functional system, and 3) having a lot less junk on my desk.<\/p>\n
I’ve now managed to get time and date stamp and temperature readings sending to a CSV file that loads easily into Excel that I can apply a chart to.\u00a0 Next up — Roasting something to get real temperature numbers.<\/p>\n","protected":false},"excerpt":{"rendered":"
Earlier in the blog I posted photos showing the circuit boards inside the roaster that were labeled 1000W.\u00a0 The roaster was reported as being 1500W and it’s a pretty major deal to be 1000W vs 1500W.\u00a0 After looking back at the blog and some of the things I’ve worked with and struggled it made me wonder more about the wattages used by the SR500.\u00a0 Additionally it seems there are a lot of people that come to this blog looking for information about how many watts the SR500 is. In the interest of providing accurate information I went out and got \u2026 Continue reading