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newbie question (water level circuit question)

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1-Yes it will. Make the 330 ohm resistors 680 ohms and the 2.2k resistor 3.9k
2- Not to difficult. Add another circuit just like the full circuit for the buzzer.
 
thanxs ronv

to be honest for me electronics are like trying to learn to read welsh.. uk ,,, with no reference point....
if its possable are you willing to teach an old dog some new tricks...

1 is it just a matter of .....double the volts ...double the resistance ....if it is ?? what about heat build up
 
Actually, if you look at the data sheet for the switch on resistance of the 4066; it is between 270 to 1000 ohms at 6v, so a resistor most likely is not even needed. At 12v the switch on resistance is around 100 to 400 ohms, so you could get by with a small value like 62 ohms.
https://www.fairchildsemi.com/ds/CD/CD4066BC.pdf

The other issue is how well the water detection works. This will greatly depend on the electrolytes in the water. In my area the water is hard and its conduction properties are very poor. To get my water to conduct, I have to put in lemon juice or salt.
 
Ohms law

It's a little more complicated than that but not much. Here is a chart that will make you an expert. :=)
Lets use the example of the LEDs. The 4066 IC has a resistance of about 180 ohms, when on, plus the 330 ohm resistor so 510 ohms total. The LED has a little voltage drop across it when its on (lets say 2.5 volts). That leaves us with 3.5 volts divided by 510 ohms or .0068 amps (6.8 ma). Total power I X E = .041 watts (not much) So when we changed it to 12 volts the IC resistance and the LED voltage drop stay the same and we end up with 9.5 volts / 860 ohms or 11 ma. and the power goes up to .13 watts. Still pretty small. So to make it just right (or the same as before) you would want the total resistance to be 9.5 / .0068 or 1397 ohms. Subtract the IC resistance and you get a resistor of 1217 ohms or 1.2k ohms. If I hadn't been lazy this is the value I would have given you. Quiz: What is the power with the 1200 ohm resistor?
 

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