NightFlight
New Member
I'm making the following circuit to handle the output of my RC transmitter unit (which ouputs a pulse signal from the rear) and convert it to a suitable signal for serial port input. The circuit is described at **broken link removed**
So far I've layed out the circuit on a bread board and substituted the one BC547 with a 2N3904 and the BC557 with a 2N3906, which I hope works out.
However, looking at the diagram, only inputs listed are the signal and ground. What drives the transistors? They require voltage if I recall (WAY back to my basic electronics course) for them to actually perform any function. Does the circuit just assume that the designer should know where the power goes? I've been re-learning alot over the last 48hrs, but some pointers in the right direction would be appreciated!
I've really got to dig out my old notes from class on transistors and calculating gain... etc. Theory and implementation do not go hand in hand however. :wink:
So far I've layed out the circuit on a bread board and substituted the one BC547 with a 2N3904 and the BC557 with a 2N3906, which I hope works out.
However, looking at the diagram, only inputs listed are the signal and ground. What drives the transistors? They require voltage if I recall (WAY back to my basic electronics course) for them to actually perform any function. Does the circuit just assume that the designer should know where the power goes? I've been re-learning alot over the last 48hrs, but some pointers in the right direction would be appreciated!
I've really got to dig out my old notes from class on transistors and calculating gain... etc. Theory and implementation do not go hand in hand however. :wink: