Ross Herbert wrote:
On Sat, 08 Mar 2008 17:57:28 +1100, Franc Zabkar
wrote:

:On Sat, 08 Mar 2008 17:37:27 +1100, Franc Zabkar
put finger to keyboard and composed:
:
:On Sat, 08 Mar 2008 05:27:08 GMT, Ross Herbert
put finger to keyboard and composed:
:
:The LDR senses dusk and
:performs the function.
:
:The solar cell is a *light dependent* sensor. It can perform the same
:function. Think about it ;-)

Logical, and understood

:
:Hmm. Here are two circuits which don't require an additional sensor
:and two that use a CdS photocell:
:
: http://members.shaw.ca/novotill/Sola...ight/index.htm
:
:- Franc Zabkar

The only ones I have pulled apart are those with the LDR.

Some of mine have ldr`s and one hasnt. the one which has no ldr powers a
string of about 30 leds by upconverting 1.5 volts to 15v pulsed.
there`s a quite complex circuit which detects whethere the cells are
producing any output and switches accordingly. It`s failed twice now due
to the leads from the cells corroding away.

Why is it always the negative lead that corrodes?

Ron(UK)