2. Why is a resistor used in the circuit? Alternatively, what would the graph look like without it?
3. Could the first voltage spike be taken care of with a voltage regulator and the second with a diode, or would both be handled by the regulator?
Well, an inductor has high impedance to high frequencies, but low impedance with low frequencies.
So without a resistor... well, never mind the graph. Here's what the circuit would look like though:
Quote from: David82 on Jan 15, 2013, 10:35 pm3. Could the first voltage spike be taken care of with a voltage regulator and the second with a diode, or would both be handled by the regulator?You mean, reducing the first spike by limiting the current?
Also, yeah.. and inductor and cap combo make a good isolator.
Another option is to feed the low-current section through a series resistor, with its own local supply cap. This will make the battery a lower-resistance (therefore, more attractive) supply in comparison.
I see. So you're making the battery the path of least resistance so that it doesn't suck the current and voltage from the camera. Won't the camera still be deprived of current though?
I have an 85mA load (analog camera) that shares a power supply with a 4A load that is occasionally switched on. Even if the power supply is a car battery, the amp draw and voltage to the camera gets sucked away briefly when the 4A load is switched on causing the camera to flicker. I was thinking a 125mA, 10H inductor would maintain the current and voltage to the camera (or at least make the transitions smoother). Is this the right thinking or should I be looking at using a large cap instead?