Good day
I have a question regarding the uploaded circuit, it is for converting a PPM signal to a USB interface found at http://www.rcdesign.ru/articles/electronics/rcusb (I know its Russian, good for google translator)
The transistor VT1 according to the author:
"PPM signal from the transmitter to the input of ICP (input capture pin) microcontroller through a matching stage transistor VT1. If the amplitude of the signal from the transmitter PPM exceeds 1.5V, you can not establish the elements of VT1 and R3, and to signal to the input of the microcontroller DD1 ICP via a resistor R2"
I do not understand the function of the resistor/transistor configuration or the reference to the "matching stage transistor". Can someone please explain to me?
I have a question regarding the uploaded circuit, it is for converting a PPM signal to a USB interface found at http://www.rcdesign.ru/articles/electronics/rcusb (I know its Russian, good for google translator)
The transistor VT1 according to the author:
"PPM signal from the transmitter to the input of ICP (input capture pin) microcontroller through a matching stage transistor VT1. If the amplitude of the signal from the transmitter PPM exceeds 1.5V, you can not establish the elements of VT1 and R3, and to signal to the input of the microcontroller DD1 ICP via a resistor R2"
I do not understand the function of the resistor/transistor configuration or the reference to the "matching stage transistor". Can someone please explain to me?