Low voltage DC to AC

I have some of those solar Christmas lights that I would like to run using my arduino. When I took them apart I discovered they operate with every other LED oriented in the opposite direction, i.e. they are never all on at the same time. To achieve a "steady" burn, I presume the native hardware is applying an AC signal with a frequency > 1khz. I would like to replicate this feature with my arduino. I have figured out that I will probably need an H-bridge but most of what I have found about these is related to motor control. Will a typical motor H-bridge support a frequency of >1khz? If not is there a recommended product? Thanks.

I doubt you need >1kHz. As long as it's fast enough for persistence of vision to make them appear to be on continuously they should be ok, so over maybe 25Hz I think.

Yes, a H bridge would probably work.

You also could switch more slowly, say 0.5Hz, to get them flashing alternately.

25Hz? Did you mean 250? We have similar LEDs, I don't remember the frequency but the flickering is too well visible at low light intensity (they are dimmable). I would aim for frequency over 100Hz to avoid this, I think 1kHz is a good value. A H-bridge should handle such frequency well.


I meant 25Hz as an absolute rock bottom minimum, but I agree it would be visible to most people.