Flashing Lights

[skccshaw]

SORRY GUYS I FORGOT TO ATTACH CCT DIAGRAM



Hi all, I'm a newby to this forum just thought I'de ask a quick question regarding a linght sensative flashing light cct I've built recently. I split it into 2 cct's the first one is a simple alternating flashing pair of LED's, this worrks fine. However the 2nd cct is to switch the flashing LEDs on when it gets dusk and switch them off again at dawn, I have attached a cct diagram of the switching cct the variable resistor is 100k, the problem I have is that the cct switches on too early (before dusk) can anyone advise me what I need to do to make it switch on when its darker? I have tried adjusting the resistor but even when fully adjusted at either end it still switches on too early. Any advise would be great.

Thanks guys

 

[ericgibbs]

hi,
Do you have a voltmeter.?

Disconnect the base of the transistor from the LDR.

Use the original 10K resistor from +V to the LDR

Measure the voltage across the LDR when 'dusk dark' and also when 'light', let us know the values.