David,
Home made devices might do as well(?).
Quote from a much earlier post, re. devices we made in the 1960-70s:
‘In 1974, vol 84, no 3 (April) page 189 D. G. Daniels describes a similar device looking a bit more like the one I built (long since gone to the scrapbox in the sky). If you’ve got a fast connection you can download a copy from the BAA (6.57Mb) a real blast from the past. If you do, then, rather than spend hours trying to scroll to the right issue do a search for time-switch (the “-” IS important!)’
Roy.