I need to power my device with three different voltages: 3.3 V, 5 V and 12 V. I already have a 12 V 1 A power supply. So my questions are:

1. **Can I use the circuit below to get these three voltages?**
2. **Is it safe when ground of LM317's is shared?**
3. **Do I need any additional diodes or anything else?**

![schematic](https://i.stack.imgur.com/KX1DE.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fKX1DE.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)