>>
Sorry for the wrong format before
but here I=B4m attaching a shema in .GIF
format on a circuit I have some problem with.
The relay don=B4t switch over directly without
stands and vibrations before it changed.
What is wrong?
<<

The gain is low and there is no hysteresis.  When the light level changes
slowly the relay will be slowly driven thru the on/off range.  One
additional transistor stage would get you lots of gain and an opportunity
to supply a little bit of positive feedback.  This will make the relay
snap on or off, although there will be a small difference in the on->off
light threshold as the off->on light threshold.


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