On Sun, 2013-09-29 at 13:20 -0400, Doug wrote: > On 09/29/2013 06:47 AM, Ralf Mardorf wrote: > > On Sun, 2013-09-29 at 19:02 +0900, Joel Rees wrote: > >> I7m confused. Did you mean can't produce a gain in current or power? > > > > Assumed there should be a linear voltage regulator able to provide the > > needed Ampere, how large should the heat sink be? The voltage isn't an > > issue. By a quick search I found a max. of 10 Ampere. My laboratory > > power supply does provide only 2 Ampere and the heat sink is > > 10 cm x 10 cm x 5 cm "small". The once mentioned in "The Art Of > > Electronics" Horowitz/Hill original 1989 Cambridge University Press, > > here the German translation 3. edition 1998 provide less than 10 Ampere. > > > > > The size of heatsinks is a function of the heat dissipated in the active > device, whether it be a regulator, an amplifier, or a rectifier, or even > a power resistor. It is then a function of the heat transfer > characteristics of the heat sink. That is dependent on the size of the > sink, but also on the number and size of the radiating fins, if any, and > the airflow around the sink, whether is is convection, or aided > by a fan. All of this is calculated by the maximum desired (or > allowable) temperature of the active device, the thermal resistance of > the device to the heatsink, and the thermal resistance of the heatsink > to the ambient air, which is usually defined as being 25 degrees C. > All of this is not done by "seat-of-the-pants" design, but by published > specifications of all the devices--the active device, the insulator, if > any, the heatsink, and the airflow. The calculations are > straightforward, but will not be related here.
Sure, some heat sinks can be smaller than others, for the same task, but assumed there should be a linear voltage regulator > 10 Ampere, the needed heat sink would be huge or a fan would be needed and as you already pointed out, the ampere input has to be as high as the output. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1380476370.1068.16.camel@archlinux