Hi all,

I'm looking for a bit of assistance with a small project i'm building.

I have a small solenoid piston pump that i'd like to control using a PIC microcontroller. The pump runs off 12V and is rated at 5W.

I have created a basic circuit that drives the pump using a BJT and a relay circuit. This works well but i've been told that i can do away with the relay by choosing a different transistor. This will allow me to reduce the physical size of the circuit.

I have limited experience with transistors therefore was wondering if someone could help with specifying the transistor and how to wire it up. I have included the circuit diagram of my current circuit.

Thanks in advance!!

Attached Images

Circuit1.jpg (44.7 KB, 21 views)

 

Please take a look at the attached image.

In so doing you must joint the 0V of both the 12V pump supply and the PIC supply or else it won't work.

You have not indicated your location so no specific part number is included in the schematic.

Attached Images

PumpCircuit1.gif (6.8 KB, 17 views)

__________________
L.Chung

 

Thanks for your reply!

I'm actually based in the UK.

Are there any specific parameters i need to specify when choosing one? there are so many different ones out there.

Cheers!!

 

One should choose a MOSFET that can withstand the circuit voltage and load current. But in your case, 12V 0.5A is a very easy requirement to fulfil.

Any one of the following will do nicely.

TO-220 Logic level power MOSFETs N-Channel

__________________
L.Chung

 

Much appreciated. Thank you!!