Hi,
I made a PIC programmer (Velleman kit) but I am having some stability problems with the device.
LED's which are powered by the main 5v bus aren't lighting when switched, so I'm trying to find a cause...
My question is... what is the Diode D7's function in this circuit?
Is it to stop negative going pulses from reaching T4?
The input through R13 is direct to a serial cable, pins 9 AND 3.
I made a PIC programmer (Velleman kit) but I am having some stability problems with the device.
LED's which are powered by the main 5v bus aren't lighting when switched, so I'm trying to find a cause...
My question is... what is the Diode D7's function in this circuit?
Is it to stop negative going pulses from reaching T4?
The input through R13 is direct to a serial cable, pins 9 AND 3.