| |
Value |
Comparison |
Units |
Comments |
| With JavaScript disabled or non
functioning, you are missing some features of this webpage. This webpage has been tested with IE6 and Firefox 1.5 |
| Watts |
2400 |
2400 |
2400 |
2400 |
W |
|
| Volts |
110 |
220 |
220 |
220 |
V |
|
| Number of segments |
4 |
4 |
3 |
2 |
|
|
| |
| Amps |
21.818 |
10.909 |
10.909 |
10.909 |
A |
The number of amps needed to produce the 2400 watts required from 110
volts
|
| BTU |
8196.43 |
8196.43 |
8196.43 |
8196.43 |
BTU/hour |
|
| |
| Total Resistance |
5.042 |
20.167 |
20.167 |
20.167 |
Ω |
This is the total resistance required to draw 21.818 amps, as measured between live and neutral
|
| Segment Resistance |
20.167 |
80.667 |
60.5 |
40.333 |
Ω |
Using the formula for parallel resistance you can work backwards to find
the segment resistance |
| End-to-end resistance |
80.667 |
322.667 |
181.5 |
80.667 |
Ω |
End-to-end resistance is the individual segment's resistance multiplied
by the number of segments |
| |
| Coiled wire length |
10 |
10 |
10 |
10 |
coiled ft |
The 22AWG wire is sold by infraredheaters in 10 foot lengths of
coiled wire |
| |
120 |
120 |
120 |
120 |
coiled in |
|
| Coiled wire resistance |
360 |
360 |
360 |
360 |
Ω |
According to infrareadheaters the 10 foot coiled length has an
end-to-end resistance of 360 Ω |
| 22AWG wire diameter |
0.025 |
0.025 |
0.025 |
0.025 |
in |
From any good wire datasheet |
| Coiled wire's outside diameter |
0.3 |
0.3 |
0.3 |
0.3 |
in |
From the website |
| Resistance per straight foot |
1.055 |
1.055 |
1.055 |
1.055 |
Ω |
|
| Weight |
557 |
557 |
557 |
557 |
ft/lbs |
|
| |
| 1' coiled wire resistance |
36 |
36 |
36 |
36 |
Ω |
One coiled foot would be 36 Ω |
| 1" coiled wire resistance |
3 |
3 |
3 |
3 |
Ω |
One coiled inch would be 3 Ω |
| |
| No. of coils in 1" of coiled wire |
39.526 |
39.526 |
39.526 |
39.526 |
coils |
1 divided by wire's diameter |
| |
| Straight length of one coil |
0.863 |
0.863 |
0.863 |
0.863 |
straight in |
Using the formula C = Π * D. The diameter is measured between the
centres of the wire
|
| Straight length of one coiled inch |
34.11 |
34.11 |
34.11 |
34.11 |
straight in |
|
| |
| Straight inch length of 10 foot coil |
4093.259 |
4093.259 |
4093.259 |
4093.259 |
straight in |
The total length if you take 10 coiled feet of wire from infraredheaters and
stretched it out |
| |
4094.787 |
4094.787 |
4094.787 |
4094.787 |
straight in |
Alternative method of calculating the straight length is to divide the total resistance (360) by the resistance
per foot (1.055), and convert to inches |
| |
4095.955 |
4095.955 |
4095.955 |
4095.955 |
straight in |
And just to triply confirm it, I weighed a 10 foot length, and it came
to 0.6128 pounds, multiplied by the feet per pond figure, converted to
inches |
| Resistance per straight inch |
0.088 |
0.088 |
0.088 |
0.088 |
Ω |
|
| Resistance per straight foot |
1.055 |
1.055 |
1.055 |
1.055 |
Ω |
This ties up with one of the web pages on infraredheaters. This
also serves to confirm that to measure the straight length of one coil,
we must use the centre of the wire as the diameter |
| |
| Coiled length needed |
26.889 |
107.556 |
60.500 |
26.889 |
coiled in |
Using the end-to-end resistance, and the ohms per coiled inch, we
can calculate the coiled inches needed |
| |
68.298 |
273.191 |
153.67 |
68.298 |
coiled cm |
| |
| Straight length needed |
917.193 |
3668.773 |
2063.685 |
917.193 |
straight in |
This figure can work out to an amazingly large value |
| |
2329.671 |
9318.684 |
5241.76 |
2329.671 |
straight cm |
| |
| Resistance of straight length |
80.667 |
322.667 |
181.5 |
80.667 |
Ω |
You will notice this equals the end-to-end resistance |
| Segment length |
6.722 |
26.889 |
20.167 |
13.444 |
coiled in |
|
| |
17.074 |
68.298 |
51.223 |
34.149 |
coiled cm |
|
| |
229.298 |
917.193 |
687.895 |
458.597 |
straight in |
|
| |
582.418 |
2329.671 |
1747.253 |
1164.835 |
straight cm |
|
| |
| Segment resistance |
20.167 |
80.667 |
60.5 |
40.333 |
Ω |
Each of the segments should have a resistance as close as possible to 20.167 ohms |
| Current through each segment |
5.455 |
2.727 |
3.636 |
5.455 |
Amps |
|
| Power dissipated from each segment |
600 |
600 |
800 |
1200 |
Watts |
|
| |
| Oven base width |
28 |
28 |
28 |
28 |
in |
Depending on the height of the oven and the angle of the side boards, the base will be
between 3 and 8 inches
larger than the top.
|
| Oven base length |
28 |
28 |
28 |
28 |
in |
| Layout spirals |
6.5 |
6.5 |
6.5 |
6.5 |
loops |
|
| Power output over area |
3.061 |
3.061 |
3.061 |
3.061 |
W/inČ |
This figure allows comparison between ovens with different sizes and power outputs
|
| Spacing between inner loops |
2.182 |
2.182 |
2.182 |
2.182 |
in |
The outer loop is at the centre of a 2" band around the board
|
| Layout length |
416 |
416 |
416 |
416 |
in |
Taking 26.889 coiled inches needed, and stretch it to 416 inches to route it around the board.
|
| Segment Layout length |
104 |
104 |
138.667 |
208 |
in |
The length of each individual segment used during layout
|
| Coils per stretched inch |
2.555 |
10.219 |
5.748 |
2.666 |
in |
Number of coils per layout inch
|
| Please note that these are "ideal world" calculations |
© Peter Botha
|
| |
|
|
|
| Conclusion: Converting a 110v/4seg oven to supply the same watts using 220v will use only half the amps, but it will take 4 times the length of nicrome wire,
witch could become expensive. The other option is to reduce the
number of segments to 2, where you would use the same length of nicrome wire as a 110/4 oven, but the power
dissipated from a single segment is now 4 times that of a 110/4 oven. The best option would be to have 3 segments, using 3 times
the wire, with each segment decapitating 1.3 times the power as compared to a 110/4 oven. |