Switch with BJT or MOSFET in a R/C car project

[lefam]

Hi,

I am working in a R/C car project that consists in hacking the car's remote control to control it with a cellphone. I am using an arduino duemilanove board (with atmega328 MCU).
The idea is to send commands to the remote control using the arduino. In fact, what the arduino should do is close some switches in the remote control.

I am in doubt if I should switch using a BJT transistor or a MOSFET one.

I have seen on a website that the BJTs are better for amplifying, while the MOSFETs are good in switching.
Does it matter using one instead of the other? Or doesnt it matter?

Thank you!!!

 

[Reloadron]

I have seen on a website that the BJTs are better for amplifying, while the MOSFETs are good in switching.
Does it matter using one instead of the other? Or doesnt it matter?

That is a pretty general statement and true to a point. Transistors switch just fine in many applications when driven into saturation. One downside of using MOSFETS as switches with PICs is the needed gate voltage to turn them on as a switch. When using PICs and 5 volts you want Logic Level MOSFETs.

For the better part as to BJT or MOSFET it comes down to your specific application. What voltage(s) and current(s)? If I want to turn on a small relay with a coil rated for 5 volts and 200mA I would opt for a BJT like a 2N2222. If I want to switch a few amps at a higher voltage like 12 plus I may lean towards a MOSFET.

Just My Take
Ron