I want to design a robot with differents modules: GPS, Soud detection, ping sensor, optical distance sensors, and more To prevent battery discharge, I wonder if I could disable modules if they are not used.
To do that I think to use an I2C port extender driving some Mosfets
My source current comes from a 7805, so max 1A to share. No need big mosfet
So my questions are:
A- Do you think it worth it? B- Which cheap mosfets could I use (DIP) ? C- What should I use? Mosfet, transistors, darlington (uln2003) ?
Unless you’re putting your Unless you’re putting your whole robot to sleep, I wouldn’t bother. MOST sensors don’t use that much power, and many sensors have an initialization time and power cost.
Most gas sensors use a decent amount of power. And I’d turn them off when not in use.
Motors can be turned off by the driver easily, and they are usually the biggest draw on current. Never tried GPS, but i guess it will be a power gurgler just like wifi.
Check transistor datasheets, they specify exactly voltage and amperage range of the gate and the signal.
I would start with the 7805. You can get switchers in the 3 pin package that are a direct replacement or get switcher modules for under $4.00 on ebay and bypass the linear completely. Remember, with a linear regulator, the voltage drop between the input and output terminals multiplied by the current passing thru the device (your load) equals the power loss.
