Usb human heater

From Technologia Incognita
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Projects
Participants Amx109
Skills
Status Dead
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

Length = 2m
Current = 5/20 = 0.25A
Power = 5 * 0.25 = 1.255W