Drawing power from a 12V car battery a 9V stabilized DC

Last updated: 6/21/2023

Drawing power from a 12V car battery a 9V stabilized DC voltage is required to power a car stereo system attached to the terminals A and B as shown in the figure If a Zener diode with ratings V 9V and Pmax 0 27 Vz W is connected as shown in the figure for the above purpose the minimum series resistance Rs must be R 12V V 9V A R 9B