Complex Light Dark Indicator

[Heith]

Howdy,

For an upcoming electrical practical exam we have been asked to design a complex light dark indicator. I have come up with a light dark indicator however according to my lecturer the circuit isn't complex enough to get the marks(why make something complex when it can be easy!!).

I have posted a picture of the circuit diagram that we have developed. I was hoping that someone might be able to come up with some ideas to show me how I could make the circuit more complex (preferrably a circuit diagram) and explain to me how it works.

Thanks for any help.

Peace.

[Mr T]

You need to teach thim the K.I.S.S. method.

Sorry no time to draw up stuff..

A> Tap off the output of your switching transistor and feed it into a flip flop circuit with your 2 outputs being LED's indicating light and dark.

B> I forget if a phototransistor is a variable output device or just a on/off. If not, get a photoresistor. You want a voltage output that changes with the amount of light.

Use a op-amp as a comparatitor with one input being the photoresistor output, and the other a variable voltage. Use this to set the level in which the device switches on at. Feed into the set side of a latch circuit. (invert the signal if necessary)

Build a 2nd op amp circuit that the output goes high when the light level drops below a threshold. Feed this to the reset side of your latch. (again invert if necessary..i dont have enough caffine in my system to think logic right now)

C> Go to Home Depot and buy a $5 day/night sensor and turn it in as your project.

[Ohm1]

I like option C..........................! :creep:

[ggratecc]

I have posted a picture of the circuit diagram that we have developed. I was hoping that someone might be able to come up with some ideas to show me how I could make the circuit more complex (preferrably a circuit diagram) and explain to me how it works.

Thanks for any help.

Peace.

I think one of the ideas he was looking for was a "time delay",
which you will find in one of those at Home Depot.

[sheldonstv]

all u need is a schmidt trigger type circuit with an orp12.......ill post a suitable schematic if u wish.........