Can electricity (Voltage/Current) flow from the emitter to collector even when the base is not switched on? I have used several NPN (BC 547) together and it does flow from the emitter to the collector, well I’m not sure 100 per cent because in my circuit I provide little current to the emitter from another stage of a circuit.
I understand that is a little bit confusing to figure out my problem but what ever you can tell will be Welcome.
Thanks

Hi , I putted a capacitor (10 Micro) at the emitter now the system is responding according to my expectations, but I still want to know what is happening.

If the base is reverse biased and the collector emitter is forward biased then yes, a very small amount of current, nanoamps can flow, if the collector emitter is also reverse biased then reverse leakage current can flow usually in the pico amps range.

But, bottom line, you cant even measure these currents without special equipment. So, if you are hooking things up right, transistors should do what you need them to do. Work with 3904 and 3906 or 2222 and make SURE the EBC are labeled correctly and you don't have them flipped around, MAKE SURE. Just because one company makes an NPN with EBC in that order, doesn't mean the same part NPN from the other company didn't reverse the order.

Andre'

Thank your Sir.