9V to 3V Step-Down Converter by LT1073
DC converters
I want mini size switching regulator,so it input voltage 9V to 3V Step-Down Converter circuit. The LT1073 is good idea,it used for dc to dc converter. if want it,please read in https://www.linear.com . Vout 3V at 100mA, L1 100?H , D1 – Diode 1N5818 or equiv Detail more,please in image. Related Links Step down converter circuits All circuit used the LT1073 Switching step down converter 3V power supply 12V 5A power supply Regulator with LM1084IT-12 LM317 Adjustable Regulator For batt 9V Supply 9VDC no transformer 9V 2A Power Supply by 78S09
Easy Power Supply Regulator 3.3V 1A  with PNP Transistor
Power supply
The is Fix dc voltage regulator about 3.3V at 1A,so easy very circuit. I used normal electronics part,so used PNP transistor 2N456 or TIP42 or TIP2955,etc. If do you want other dc voltage,you must change ZD1 : 5.6V for 5V out put. I made use of a 6.3Vac transformer,The output of the transformer is rectified and smoothed using 1500uF or 2200uF capacitors. The float-voltage measured here for the 6.3V transformer was 8.4V. The unregulated DC is regulated by the Q1 PNP Transistor and ZD1 to give the regulated supply rails for the circuit. If do you want detail more,please read …