hey ..
there is the circiuit diagram of Light/dark detctor..
please tell me how it will work..?
i mean when there is dark..so what will be the respone??
the realy wont wokr..thats it..!
i dun have to put any led or some thing to show it clearly..???
please senior members help me out
hey ..
there is the circiuit diagram of Light/dark detctor..
please tell me how it will work..?
i mean when there is dark..so what will be the respone??
the realy wont wokr..thats it..!
i dun have to put any led or some thing to show it clearly..???
please senior members help me out
hi,
When Q2 is dark it has a higher resistance compared to when its lit.
So as Q2 gets darker the the voltage on Q2 collector will rise, this will increase the base votage of Q1. This increase of base voltage will make Q1 conduct more current thru the relay.
Eventually this increase in Q1 current will enegise the relay.
When Q2 gets more light its resistance falls, which reduces the Q2 collector voltage and so Q1 base voltage falls which causes a reduction in Q1 current and so eventually the current falls low enough that the relay de-energises.
The pot in the collector of Q2 is 'supposed' to enable the setting of the point of light/dark, when the relay operates.
The circuit is a poor design, where did get the design from.?
well thanks for explainging...!
but may i ask that what do u mean by poor design?
is it mean that if i implement it so it wont work or what??
please make me clear this thing cus i m supposed to start work on it by tomorrow..
thanks again for ur explanation
well thanks for explainging...!
but may i ask that what do u mean by poor design?
is it mean that if i implement it so it wont work or what??
please make me clear this thing cus i m supposed to start work on it by tomorrow..
thanks again for ur explanation
First thing, i Didnt make this Circuit i jus got it from the net..
and the other thing i didnt start working yet..
ill do it tomorrow..
u mean this Circuit will give hard time?
how to connect Pot.
listen if i set the pot when the relay is energised and the light is on the photo.TRan,
so will the relay stop when there is no light on the phot.Tran..?
or do tell me how to set this Pot..:s
well the pot is connected as 1 leg to the 9v and the other one is connected to the Q2 collector and Q1 base..
m i right???
First thing, i Didnt make this Circuit i jus got it from the net..
and the other thing i didnt start working yet..
ill do it tomorrow..
u mean this Circuit will give hard time?
how to connect Pot.
listen if i set the pot when the relay is energised and the light is on the photo.TRan,
so will the relay stop when there is no light on the phot.Tran..?
or do tell me how to set this Pot..:s
well the pot is connected as 1 leg to the 9v and the other one is connected to the Q2 collector and Q1 base..
m i right???
If it's for University work then I wouldn't expect to get any sort of decent mark at all for handing something like that in - as suggested, it's an incredibly poor circuit, probably 'designed' by a 9 or 10 year old?.
Presumably you're not doing an Electronics degree?, as you wouldn't get on the course if you need to ask such basic questions.
No its not mentioned the relay coil Voltage..is it necessary?
the photo transistor is the Q2 not Q1.where Q1 is simple npn 3904.
please make me clear bout pot..
how to set it?
ya Nigel
i jus wanted to know this thing that is it acccpetable by the teachers whom i have to submit..
because i didnt work on this type of project..
so i jus search on the net & found it..
i have to work nething BJT with sensing..
well thanks for ur comment !!