Just one more thing,

how did you get/calculate 470ohm value for base resistor?

I guess not by the formula 6v/0,094

No. Remember that the voltage out of the PIR is not 6V, but is 3V. However, I actually got the value by measuring the total collector current and substituting values of base resistors until the collector current was at the maximum. That turned out to be 470Ω for the base resistor.

I have ordered more of the PIR modules, and am planning to use them in an electronic scarecrow that will move and make noise when crows (or other animals) come in my garden.

Good luck.

 

Another question - i guess a bc 547 is fine, and it's rated to 30V and 0.1a, i guess that's means that he can conduct only 100 mah of current (approx. 5 led)?
regards

Hi,

Do you mean 100ma of current? Or 100 milli-amps? Using 100mah is confusing, as that usually mean "milli-amp-hours" which is a measure of energy, and not current.

 

Sorry, i meant "mA"