Difference between revisions of "Usb human heater"
| Line 34: | Line 34: | ||
Length = 0.5m | Length = 0.5m | ||
Current = 5/32.5 = 0.156A | Current = 5/32.5 = 0.156A | ||
| − | Power = 5 * 0.156 = 0. | + | Power = 5 * 0.156 = 0.78W |
== 10ohm/m == | == 10ohm/m == | ||
| Line 44: | Line 44: | ||
Length = 1.5m | Length = 1.5m | ||
Current = 5/15 = 0.333A | Current = 5/15 = 0.333A | ||
| − | Power = 5 * 0.333 = 1. | + | Power = 5 * 0.333 = 1.665W |
Revision as of 21:14, 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
