If you’re not familiar with the 555 timer, suffice it to say that this ... Hans sadly passed away in 2012, but you can hear some audio clips of him discussing the 555 at the Transistor Museum ...

As it turns out, the ever-useful 555 timer chip does the job admirably. It’s a simple enough circuit, the threshold pin is pulled high so the output goes high, and the PWM drive from an Arduino ...