Vehicle Speed Sensor

I am currently building a vehicle speed sensor for our chump car series car. I have the sensor built and the code pretty well established but I am having an issue interfacing the Arduino to the ECU. The ECU is expecting a signal from the sensor at 12v and 100k pulses per mile. I know there are several ways to accomplish this but I thought the collective arduino community might lead me in the most effective direction. The kicker is that at 200mph (optimistic I know, but we do expect to see speeds in excess of 145 on some tracks) the circuit needs to switch at over 5kHz.

Long story short, how would convert 5vdc output from the arduino to 12v output.

Note: I would love to use something like an optocoupler or SSR to isolate them, but I have not seen an optocoupler that can handle 12v, or a SSR that has a fast enough switch time.

Note 2: I really don't care if the signal lags a little. Just that the wave forms are identical except the amplitude.

Thanks guys and gals, Paul

The 4N25 optoisolator has max 70V for Vceo. Should be ok at 12V.

Weedpharma

output from arduino to optic isolator, output from optic isolator to an SCR or transistor.

Thanks weedpharma, that's exactly what I was hoping to find. Looks like I need to brush up on my mouser search skills.