I am working on a project to control a latching solenoid via radio control. The solenoid is a dual position solenoid using a magnet to latch in the retracted position. The solenoid will not work properly unless current is limited to between 0.75 and 1 amp. It's resistance is 3.3 ohms so it naturally wants to draw upwards of 4 amps from a 12 volt source. My knowledge of electrical components is not very deep but I took some courses in college and have a general knowledge of basic circuits.

I am planning to use a 2 channel RF receiver in combination with an L293 quadruple Half H-Drive to control the solenoid.

I am concerned with limiting the current to a value between 0.75 and 1 amp and do not know an effective (or generally acceptable) method of doing so.

My thought was placing the whole circuit as a load on a transistor which I will size a base resistor accordingly to supply only 1 amp through the emitter. I am in a little over my head at this point and any pointers would be greatly appreciated.

I have attached a drawing for reference.

 

How long does the solenoid have to remain powered after its initial pulse?

 

Momentarily. <1 second probably more in the 0.25s to 0.5s range.

Edit: The duty cycle will be very low. Activated once every 30 minutes or so

 

A typical RC Li-Po battery supplies many amps for motor and servo's that load would be trivial for even a small size.
Max.