For that, you just need to not make the transition from 100% duty cycle to 0% duty cycle instantaneous, but to ramp down linearly the duty cycle over a large fraction of a second or even an entire second.
As another poster said, the overshoot may look cool, but I would be worried that a cheap panel voltmeter would not survive a very large number of such shocks.
As another poster said, the overshoot may look cool, but I would be worried that a cheap panel voltmeter would not survive a very large number of such shocks.