Night Clock

[willstewart]

As much a test rig as a final object but might inspire some interest.  Challenged to make an interesting clock I made up this, which consists of a purchased 'skeleton' quartz movement in a simple tulipwood (walnut footed) surround but with a 'night light' (Amazon Wireless Night Light, £15 for 3) fitted behind the clock.  This self-contained USB-rechargeable unit detects 'night' (darkness) during which the light is triggered 'on' (30s) by local human movement, detected the central PIR sensor.  The effect is that at night the clock lights up if one stands in front of it.  Although the central PIR sensor is not ideal it can see past the open clock movement sufficiently to operate.  See lit and unlit pictures and another with a spare light unit with charging cable plugged in to show scale.

Lamp battery life with the light unit in 'auto' mode (24/7) is still unknown but weeks anyway.  A wrinkle is that any front clock glass tried so far (glass or acrylic) blocks the PIR sensor so the unit here is open. Also I drilled small holes in the numeric clock face to make the number positions more visible when backlit at night.

There is clearly room for idea variants (even an actual night light!), offcentre turning etc.  It is apparently possible to leave the unit plugged in to avoid any light battery life issues (of course the clock battery is separate).

Anyway an interesting thought for you all.

[bodrighywood]

Love seeing people try something different and this is different. Be interetsed to see what varui=iants you come up with.

Pete

[willstewart]

A variation - the plastic light diffuser on the lamp can be unclipped and has here been replaced by an inverted small wooden bowl with many 8mm holes in. The PIR can see through the holes and the small LEDs cast interesting shadows through them - a possible child-waving-operated night light?

[willstewart]

and final unit

[Mike313]

I admire your creativity

[willstewart]

This is an extension experiment which cannot really be shown in stills but is much too large as a movie. I solder replaced the 6 white LEDs with 6 slow-colour-changing LEDs.  These are amazingly cheap (& come in single LED style plastic packages) and shift colour gradually over a wide range on a timescale of a few seconds, covering the whole spectrum.  The 6 get out of sync quite quickly so the idea was that one would get a shifting never-repeating pattern of different coloured patches on the ceiling. This sort of works but there are two problems - firstly the average colour is rather dominated by blue-green and secondly the LEDs are a bit dim relative to the white ones. 

The pics do not really do it justice and are taken before the LEDs get too far out of sync (so the LEDs are similar coloured).

All the same the white (fixed) patterns work better I think