Run a RPI 1 from a RPI 4

Hello, Just some data for the question: RPI 1 Power: 5V Max 1.2A Min. 500mA RPI 4 delivers through USB 3: 5V 1.2A Would it be possible to run the RPI 1 through the USB RPI 4? Yes, am aware enough power is delivered, but maybe someone got some information if its bad or good idea?

Wdym run through the usb?

As in your going to power the pi 1 completely through the pi 4s usb? Yes that's a reasonably bad idea.

The pi 4 is not meant to power devices like that, it could cause stress on the pi and may fluctuate in power delivered meaning it will not be stable at all + may brick the pi 1 and maybe even the pi 4 depending on if the pi 1 asks for too much power (im not sure about that last part don't have enough information about the pi 1)

There is a FAQ about that, Check the FAQ section.

Wow forgot we had that