Circuit that lights LED when LDR goes dark ?

[deadastronaut]

  'path-finder pedalboards'...catchy name!..

ive got a couple of those solar lights on my balcony...will have to take one apart, and have a look..and get told off  by the missus..

'poundland' sells lots of those for guess what.. a pound each...not bad for all the bits considering craplins want nearly 2 pounds for just an ldr...hmmmm....

[petemoore]

   this one has [had] 2 nice LED's and some kind of magfield sensor [hall I suppose.
  It's too bad the parts are too small to find on the board, perhaps one day I'll ferret out or rewire the sensors to a new power supply.
  Kind of a shame these are funny batteries in a 'dissamble 'n try to solder new ones in' kind of construction...at least I'm getting the LED's and may find some use for the lens cover.
  They were cupboard lights, they come on when the light comes through the door. Not bad but the sticky back deal and magnets...makes 'em fall off, then the little mag-plate thing gets lost and the stay on and...
  Anyway, using the little LED lights when LDR gets dark circuit in my new Tube Reamer, I have it fixed with a 100k ''large'' and it makes 2x or so ''boost''.
  While the amount of cut [which I called boost in the last sentence] of course was intended as large to start with so to be certain the system is working, and will be either switch/reduced or fixed R across the R to bring the LDR max R lower.
  It does require a fair amount of light and isn't really controllable like a volume pedal, point A min, and point B 'max' via careful choosing of peripheral resistors seems to work well, modest, smooth increase of volume for 'lead-boost' was the goal.
  It is cool, and does 'pretty smooth', I think I can work with it.
  Just whipped #2 since #1 is installed for field tests.
  Recommend: Power supply for this. I have power LED, and series LED's for Attenuation [to LDR] and attenuation monitor LED [through top panel.
  Smooth And gradual sweep is the goal for round 2, to make the sweep similar to what a min/max stopped volume treadle control [one that works real nice] might achieve. 
  I'm sure I'll want good gradual control if I can get it, all possible Q set or sweep controls for the Neutron Filter, all 3 driver control types [LFO too], and a rotary switch for the LED.   

[petemoore]

  i have 7 from 10pack of hall effect type lights.
  The magnet moves away from the PS/LED/sensor circuit and the LED's light.
  Second hand store stickyback tape failures and "hard to get to even if changable'' battery supply...I think I can even find the rest of them.