The first item is a circuit that automatically resets an infant swing. [Jay], who built both items, has an infant swing for his daughter that spins a mobile and plays music. It’s great but it only works for 7 minutes and 15 seconds before a button push is required to trigger it again. He found this limitation to be annoying, and as I have owned the same swing, I can echo his frustrations. He probed the swing and found that a 5v pulse was required to reactivate the mobile, but it had to be sent after it turned off to have any effect. He put together a simple circuit that would do the button pushing for him, as you can see in the video below.
[Jay’s] other entry is a headphone tube amp using a quartet of 6DJ8 vacuum tubes. The 555 timer in the amp is used to drive a FET and the hand-wound transformer he built for the amp. You can see a video of the amp in action below as well.
The projects are lacking a thorough write-up, but he does provide schematics for both the swing reset switch and the tube amp for those looking to replicate either item.