For my application, I need three voltages +5V, +15V, -15V
Initially, I was using wall socket plugs to connect two 15 volt adaptors, in which I connected the + and - together and considered it as ground, and used that common ground connected to another wall adapter (5V)'s negative to get a common ground, and all my voltages +5V, +15V and -15V.
Since this is cumbersome, I wanted to streamline my power supply, I got a USB-C PD adaptor (capable of giving 20V), and three off the shelf module of LM2596 from amazon, along with a USB-C PD power negotiation chip (zy12pdn). However, wiring it up as mentioned above leads to a short.
Below is the circuit diagram that I am using, previously it was wall adaptors, now its buck converters, now this leads to a complete short and stops USB-C PD from working.
- Can adding diodes help the situation?
- Is there something wrong with this approach?
- How can I fix it?