voltage regulator using zener diode
9V Regulator low current Supply
mini power supply regulator give friends try out again. Be fixed voltage regulator 9V size. It uses transistor be pillar equipment perform boost up current tallly go up about 300mA. And by have Zener Diode perform steady voltage at 9Vdc. The detail is other a friend sees in the circuit please yes
http://www.elecfree.com/electronic/9v-regulator-low-current-supply/