Hi guys,
I need to create a power supply for sim900a module. Sim900a required voltage is 3.6 to 4.5v and 1A current. I designed a circuit with 1k ohm resistor and 3.9v zener diode. In that circuit the input voltage is 12vDC connecting 1k ohm parallel to 3.9v zener diode. I got this circuit by google searching zener diode voltage regulator. Im getting 3.9v output, but I'm getting 0.01 A. Suggest me good power supply to produce around 4 volt and 1A.
4V is not a common supply voltage ( however it's possible to find it by deeper searching) but the simplest solution is to use a simple and easily available LM317 adjustable regulator and to adjust the output voltage by fixed resistances.