This is a very simple led constant current design using only 2 transistors, 2 resistors and an LED. This circuit allows you to use any voltage between 2V and 24V to drive almost any type of LED with ...

Battery level indicators generally detect the voltage levels of the batteries to give a result. So, tester circuits must not be a heavy load during the measurement process. This tester circuit draws ...

[Dino] is back with another installment of his Hack a Week series, and in this episode he is taking on what he promises will be the last transistor-based project – at least for a little while. In the ...