I have a bunch of 5V devices (Raspberry Pi and Arduino devices, and LED strips) that need a power supply. I'm currently using a bunch of transformers from BTF Lighting (the ones shown on the image below, not the black ones) which work well, but have one major caveat: they all consume four to five watts of power, even when not powering anything at all.
When the number of those devices is limited, this is not a big deal. However, as I do more and more “smart home”-type projects, 5W multiplied by the number of transformers remaining on permanently starts to be problematic.
Ordinary phone USB chargers have a consumption of less than 0.1W when not powering anything. I would be glad to use them, but they are mostly rated 2A or 3A. This is perfectly fine if I need to power a Raspberry Pi, but not OK for a LED strip (5V, 4A transformers from BTF Lighting were heating a lot when used with one strip + Raspberry Pi + Arduino, so I'm relying on 5V, 12A transformers, or on 20A transformers when needed).
So, where can I find a transformer which would match the following requirements?
- Be as energy efficient as the high quality USB phone chargers.
- Have the same format as the transformers on the image above (i.e. screw connectors).
- Have 5V 12A and 5V 20A variants.
- Include over-voltage protection and short-circuit protection.
- Cost less than $40.