PorkRhombus wrote:Why do you think a FET would be better? It will be harder to get nice sharp ON-OFF transitions with the FET (you would need a gate drive circuit). I would start with just a 2222, wired exactly like one of the existing drivers (i.e. driven from the 2907A PNP). Actually I would add a base resistor of about 47 ohms to the 2222. The 2222 is rated for 600mA max and above that its effective resistance rises steeply, perfect for your target current. You don't need a heavyweight driver circuit because your "1W driver" is only ON about 1% of the time.
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