bristou
Newbie
I want to convert a PWM signal (from my micro-controller) to a DC voltage (varying between 0 and 3.3V). A simple RC circuit does the trick. However, as I am not too sure what's the impedance of the next circuit (a motor controller), I would like to add a buffer. Using a LM324 with +/- 12V supply it works perfectly on my breadboard. Now, on my robot I don't have a negative voltage, I only have 3.3V, 5V and 12V (from an arduino). Although the 324 doc says it accepts single-supply, I understand that this is only for ac operation (using vcc/2 as a reference voltage). A simple voltage follower montage with 0/12V supply gives 0V at the output regardless of the input voltage...
- Is there any solution besides getting a negative voltage supply?
- If not, how can I get a negative voltage?
In the worst case I can get a AC-DC (12V) converter to create the -12V but since I only need a negative voltage only for that small problem, I'd prefer a more elegant solution, that would only rely on the 3.3V, 5V and 12V available sources.
- Is there any solution besides getting a negative voltage supply?
- If not, how can I get a negative voltage?
In the worst case I can get a AC-DC (12V) converter to create the -12V but since I only need a negative voltage only for that small problem, I'd prefer a more elegant solution, that would only rely on the 3.3V, 5V and 12V available sources.