Nov 17, 2011 #1 V Vermes Advanced Member level 4 Joined Aug 2, 2011 Messages 1,163 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,316 Activity points 22,318 The system consists of a voltage divider on photoresistor and potentiometer, Schmitt flip-flop and signal inverter on transistors BC547 and emitter duplicate also on BC547. List of components: R1 – photoresistor R2 – 10k R3, R4 – 200ohm R5 – 9,1k R6 – 100k R7 – 510ohm R8, R9 – 10k PR1 – 10k Q1, Q2, Q3, Q4 – BC547 D1 – 1N4148 D2, D3 – LED 5mm C1 – 100nF REL1 – 4078-2C-5V-0.2 ARK1, ARK2 – 3 x 5mm Parameters: supply voltage: 5V – 12V power: 0,31W – 0,90W @ 12V 0,06W – 0,15W @ 5V dimensions: 47mm x 41mm x 15mm Scheme: https://obrazki.elektroda.pl/3456071000_1312739576_thumb.jpg][/url] Pictures for making the PCB: [img]https://obrazki.elektroda.pl/9022943200_1312739576.png Photos of the PCB and assembled system: [url=https://obrazki.elektroda.pl/8402097900_1312739572.jpg] Video with operation of the system: Link to original thread – Włącznik zmierzchowy z histerezą Last edited: Aug 10, 2012
The system consists of a voltage divider on photoresistor and potentiometer, Schmitt flip-flop and signal inverter on transistors BC547 and emitter duplicate also on BC547. List of components: R1 – photoresistor R2 – 10k R3, R4 – 200ohm R5 – 9,1k R6 – 100k R7 – 510ohm R8, R9 – 10k PR1 – 10k Q1, Q2, Q3, Q4 – BC547 D1 – 1N4148 D2, D3 – LED 5mm C1 – 100nF REL1 – 4078-2C-5V-0.2 ARK1, ARK2 – 3 x 5mm Parameters: supply voltage: 5V – 12V power: 0,31W – 0,90W @ 12V 0,06W – 0,15W @ 5V dimensions: 47mm x 41mm x 15mm Scheme: https://obrazki.elektroda.pl/3456071000_1312739576_thumb.jpg][/url] Pictures for making the PCB: [img]https://obrazki.elektroda.pl/9022943200_1312739576.png Photos of the PCB and assembled system: [url=https://obrazki.elektroda.pl/8402097900_1312739572.jpg] Video with operation of the system: Link to original thread – Włącznik zmierzchowy z histerezą