think that it is safe to say that most of the people who make (big or small) electronics-projects have a pc or laptop in theire hobbycorner and a lot of projects need 5V for IC’s or microcontrollers. So using power from a USB cable isn’t that farfetched and lets face it: a lot of devices around us use a USB-connection to get their power or to charge their batteries.
About USB-connectors and power
For this tutorial you can use any USB-connector you like (or you can even cut the cable and solder the wires) but I will use a B-type. The pins always have the same function for all types of connectors.
Voltage = 5V
max Current = 500mA
What do you need?
In this tutorial we will make a very simple power supply with only the USB-connector and a power-on led. But you can add whatever you fancy such as a power on/off switch or or a regulator to get 3,3V (fused or not) or……..
So for this Instructable we need:
- USB B connector
- Some headerpins
- An LED
- A 150Ohm resistor
- Something to hold the lot together
- soldering iron and solder
Lets get our hands dirty
Soldering everything together is actually very easy.
- Connect the led with pin1 (Vcc) of the USB-connector and then connect it to pin4 (ground) with the resistor inbetween.
- Connect pin 1 with one pin of the headerpins and pin 4 with the other.
- I soldered another pair of pins to the board but they are not connected. They just give some extra stability when connected to the breadboard.