Active low transmitter question

[LEDave]

As an aside. Has anyone used a 2N7000 Mosfet attached to a 3.3v pic output to drive a relay?

The schematic (link below) is exactly what I want to do from a pic output pin rather than the Receiver output pin.

http:///www.rfsolutions.co.uk/downlo...elayOutput.pdf

Any thoughts appreciated as ever.

Dave

[peterdeco1]

Never tried 2N7000 but for 3V outputs, we use an IRLZ44N. It's a power mosfet that we use to switch up to a couple of amps without needing a heatsink.

[LEDave]

Thanks for the reply peterdeco1 - So would that be the same wiring / resistor configuration as the 2N7000 (see link diagram) a straight swap in other words?

[peterdeco1]

Yes, although I use a 47K across gate to source. Either way it will work. EDIT Note there is a L in the part number for Logic Level. It is NOT the standard F.

[LEDave]

Thanks again peterdeco1 - If there's two parts to order from, I'm the guy who orders the wrong one (but not in this case thanks to you).

[richard]

As an aside. Has anyone used a 2N7000 Mosfet attached to a 3.3v pic output to drive a relay?

what relay ? specs ?


2N7000 specs are admirably suitable for low voltage / low coil current relays





an IRLZ44N to drive a smallish relay is way overkill

[peterdeco1]

I agree Richard. It's like putting a Ferrari engine on a lawnmower. At work we have a small PCB with an 8-pin PIC and 4 of these mosfets. It replaces about a dozen different subassemblies in products all governed by the PIC program. These transistors sometimes simply switch a string of LED's on and off, a 2A DC motor or a combination of the two. That's why I am "programmed" to using them.