What's the best way to solve this?
you can dim the lambs
This keeps the "unlit" lambs at just the npn's Vce - should be 100mv or so and those "unlit" lambs should not be visibly light.
Then dimming doesn't work
2) reroute your pwm signal to the hs595's OE pin(s).
(snip) ... a filament can not react fast enough to be dimmed by PWM due to the thermal lag. The control region is very narrow.
it is how household dimmer switches work.
you could just PWM the whole chip using its output enable pin
Or you could directly PWM the outputs themselves
QuoteOr you could directly PWM the outputs themselvesThat would require tremendous amount of data being sent over the spi. I would say that's practically no-workable.