Difference between revisions of "Usb human heater"
(→Heating Element) |
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| Line 23: | Line 23: | ||
= Heating Element = | = Heating Element = | ||
| − | P = VI | + | P = VI<br> |
V = IR | V = IR | ||
== 65ohm/m == | == 65ohm/m == | ||
| − | Voltage: 5V | + | Voltage: 5V<br> |
| − | Resistance: 65ohm | + | Resistance: 65ohm<br> |
| − | Current: ? | + | Current: ?<br> |
| − | Length = 0.5m | + | Length = 0.5m<br> |
| − | Current = 5/32.5 = 0.156A | + | Current = 5/32.5 = 0.156A<br> |
| − | Power = 5 * 0.156 = 0.78W | + | Power = 5 * 0.156 = 0.78W<br> |
== 10ohm/m == | == 10ohm/m == | ||
| − | Voltage: 5V | + | Voltage: 5V<br> |
| − | Resistance: 10ohm | + | Resistance: 10ohm<br> |
| − | Current: ? | + | Current: ?<br> |
| − | Length = 1.5m | + | Length = 1.5m<br> |
| − | Current = 5/15 = 0.333A | + | Current = 5/15 = 0.333A<br> |
| − | Power = 5 * 0.333 = 1.665W | + | Power = 5 * 0.333 = 1.665W<br> |
Revision as of 21:15, 10 January 2014
| Projects | |
|---|---|
| Participants | Amx109 |
| Skills | |
| Status | Planning |
| Niche | Electronics |
| Purpose | Fun |
After seeing the latest in hipsterly-wanky-named products, and suffering from cold hands all the time, i thought - why not build my own.
this is an attempt
Research
from [1]
In other words, on average the skin absorbs about 80 mW/cm2 to reach 41oC. In addition, skin temperature increases by 0.8oC for each 10 mW/cm2 of absorbed power.
Materials
http://www.conrad.nl/ce/nl/product/429066/Weerstandsdraad-63-m-5-m http://www.conrad.nl/ce/nl/product/429023/Weerstandsdraad-10-m5-m
Heating Element
P = VI
V = IR
65ohm/m
Voltage: 5V
Resistance: 65ohm
Current: ?
Length = 0.5m
Current = 5/32.5 = 0.156A
Power = 5 * 0.156 = 0.78W
10ohm/m
Voltage: 5V
Resistance: 10ohm
Current: ?
Length = 1.5m
Current = 5/15 = 0.333A
Power = 5 * 0.333 = 1.665W
