I'm trying to use a unipolar hall effect sensor as a power switch to turn off and on a 12V strip of LEDs, powered by a 12V 6.6Ah battery. I just tested the current draw of the LED strip with a multimeter and got a value of 442mA (much less than the 5A the seller on ebay claimed… maybe they weren't taking into account the resistors that were already integrated in the strip?).
I've seen some Hall effect sensors that can handle up to 500mA, but some of them are a bit expensive and I already purchased some of these. They're rated for 4.5-24V, with a continuous Output current of 25mA. It's supply current is 9mA (not sure if that's important).
If I use a resistor to limit the current that the Hall effect sensor gets, that would also make the LEDs appear less bright too, right… or am I wrong? Using ohm's law, it looks like a 480 ohm resistor is what the hall effect sensor needs (12V/0.025A = 480 ohm resistor).
Would it be possible to use an N-Channel MOSFET between the 12V 6.6Ah battery, hall effect sensor and LED strip, or would I need a microcontroller (arduino/attiny) and a 5V regulator to do that?
I'd rather avoid using a microcontroller, and keep this as cheap as possible unless there's no other way to avoid majorly affecting the brightness of the LEDs.
Any advice would be appreciated, Thanks!
Best Answer
I just got a reed switch and it simplified things. just connect one end to the LED strips positive lead and the other end to the batteries positive terminal.
Here's an example of one