Tag Archives: 9V

5V Regulator Cap for 9V battery

David Cook built a 5V regulator to sit atop a 9V battery:

For quick portable projects and temporary hacks, it is often faster to reuse a simple 5V regulator circuit than to integrate a power supply into the device design. My toolbox has an LED tester and magnifier light, so why not add a convenient 5V regulator cap to the collection? There are nicer ones on the market that have surface mount components, but half the fun of an electronics hobby is creating something basic in your own style. This double-decker board with flashing LED power indicator allowed me to experiment with flush battery snaps and board interconnects.

5V Regulator Cap for 9V battery – [Link]

snapVCC – A snap-on regulated 3.3 V/5 V power supply

by Mahesh Venkitachalam @ hackaday.io:

I use 9 V batteries for a prototyping a lot of my electronics projects. I was inspired by the Sparkfun breadboard power supply board, and wanted to create something similar, but with a more convenient form factor for use with a 9V battery. The design I came up with, is a tiny snap-on PCB with the regulator components on one side, and 9V battery contacts on the other. The idea is that the power supply will become part of the battery.

snapVCC – A snap-on regulated 3.3 V/5 V power supply – [Link]

9 VDC Regulated Power Supply


Tiny low current 9 VDC Regulated Power supply designed around bipolar transistor and zener diode. The circuit is known as series voltage regulator or emitter follower voltage regulator. The unregulated supply fed to input and the circuit regulate the voltage and provide constant 9V DC, 250mA. The zener diode provides the reference voltage to the base of the transistor. This is very suitable power supply for small projects as it can provide any supply output by changing just the zener diode.

Other output voltage can be obtained by changing the zener diode

Output Voltage Formula Vout=Vz-VBe

Vz=Zenner diode Voltage, VBe=0.7V

9 VDC Regulated Power Supply – [Link]