Hi Rodrigo, For some reasons [1], getting an iPhone hot is trickier than it looks and engineers have worked hard to make this device's operation as energy-efficient as possible.
The only way to make an iPhone heat itself, when not connected to a power source, is by draining its battery power as fast as you can in the most inefficient way possible. The quicker you drain the battery, the less efficient you use that energy, the hotter the device gets (users may not thank you for that). And then you hit this little snag where you can't really control efficiency. Apple engineers made sure iPhones would dissipate as little heat as possible for their operation in order to maximize battery life. So, you're left with controlling the power: the rate at which you spend (drain) the device's battery energy. As you mentioned before, getting the iPhone hot can be achieved by transmitting data over the phone network (3G) or as Alex Zavatone pointed out, you can load the cores (code for such task should be available in some open source tools for linux, achieving this goal on x86 processors). But, that's it. You don't have a lot of flexibility and depending on your specifications it may not be enough (you can't drain the battery in a snap). To give you a more accurate idea of what you can get: An iPhone 4s fully charged stores approximately 19 kJ of power (1.432 Ah; 3.7 V). Using 60% of this energy (from 80 % charge down to 20 %) you get roughly 11.5 kJ. That's the energy required to heat 270 mL of water up by 10 °C (10 °K; 18 °F). And that's only if you proceed really quickly and you get 100 % of your energy in the form of heat (which you won't). Real-world result *will* be worse (The water is not the only thing you heat, you also need to heat the phone. And both are passively cooled down by their environment, so you have to act fast, which is not possible => power control…). It may not even be enough to really heat your hands in cold winter (let me know). Moreover nice chemical devices are commercially available that nicely do the job without killing your mobile's battery life. This is just an "order of magnitude" assessment. An apple engineer would have more data to help. Or you can look on the internet. Maybe keywords such as "Joule power iPhone" could do the trick. With all the tear-downs going on for each iPhone launch I wouldn't be surprised to find some informations on this topic… Cheers, Jean [1] Usually, heat is viewed as an energy wasteful side-effect of electronic devices operation plaguing the industry. Heat is especially bad for mobile devices with limited power supply since it further the reduces the amount of energy actually available for their operation and drains their batteries. Jean Suisse Institut de Chimie Moléculaire de l’Université de Bourgogne (ICMUB) — UMR 6302 U.F.R. Sciences et Techniques, Bâtiment Mirande Aile B, bureau 411 9, avenue Alain Savary — B.P. 47870 21078 DIJON CEDEX T: +333-8039-9037 F: +339-7223-9232 E: jean.sui...@u-bourgogne.fr http://www.icmub.fr/185-JEAN-SUISSE_?id=331 On 8 août 2012, at 21:58, Rodrigo Zanatta Silva wrote: > Hi. I am thinking to do a funny program that make the iPhone to be HOT. I > intensionally want the device increase your temperature. > > Using the iPhone, I knot it will be hot if I use the 3G Internet. > Programing, I can try the program continually transfer files. > > What other strategy I can use to do this? Any idea? > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/jean.lists%40gmail.com > > This email sent to jean.li...@gmail.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
