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Dark Sensor with LDR, transistor and a LED
why only bc547 type of transistor is used why cant we try with anyother one?
use npn transister what you want it makes you job ,like 2n23904,2n2222,bc547,bc548,bc550,mbs8090,2n2369 ,etc to check use protuse software
no more 680k is used use only 680k===10-50k;1k,or less than that
Hi, How can I use a power supply of only 5v?
Hello. I just wanna ask, what are the use of every component in this circuit. Like why it has to be a 1k and 680k resistor? I need this for my finals. Thank you.
interchange the LDR and resistor
use a relay
It works very nice. Though I'd like to know if there is any way to switch the LED on and off suddenly and not just gradually, depending the amount of light. Hope it makes sense.10x
what's the use of transistor in this actually???
Uhgh. Can someone help me? Instead of LED, i want to use a motor(that dynamo thing.) Is it possible? Can u show me how?
how can i make this circuit more sensitive? please reply fast as much as u can becoz i have to give my model on 30 jan
The circuit works but the led is extremely dim.
I have made my project but the thing i wanna add is i want to switch my leds upon the intensity of lighti.e if there is low light two leds would on or if there is high then 4 how it is possible ?
The transistor is like a switch here. When it's dark, the LDR will have a very high resistance, so current will flow through R2, through the base and emitter of the transistor, thus "turning on" the transistor. Because of that current can flow through R1, the LED, the transistor and in to its collector and out through the emitter. That's why the LED will light.When it's light, the LDR's resistance drops (that's how it works). The current destined for the base of the transistor will be diverted throught the LDR, preventing the transistor from turning on thus the LED will not light.I hope that's not too difficult to understand :).
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