WSPepsilon
New member
Hopefully I do t blow it all sky high when I plug it in...
I know right!?
Sent from my Samsung Galaxy Note 2
Hopefully I do t blow it all sky high when I plug it in...
To answer your question the RC at the input of the circuit form a single pole filter. The cutoff frequency = 1/(2*pi*R*C) In this case that would be 16 Hz This will provide approximately 40 dB of rolloff at 488Hz the PWM freq of the Arduino. My self I might add a second similar pole, just duplicating the RC part.
The opamp circuit is a standard Non-Inverting amplifier. It is used so that a positive voltage becomes a bigger positive voltage. The gain is set by the resistors R2 and R3. Gain = 1+R2/R3. The circuit is thus intended to take a 5v PWM signal and convert it to a 0-10v DC signal where the higher the positive duty cycle of the PWM signal the higher the DC voltage.
Hope this helps,
Mark