LEARNING CURVE

I’d like to expand on what I’m calling my “Junk Box Series” of columns. My first foray into the junkbox focused on resistors. This month, let’s look at capacitors (Photo A). Just like resistors, a healthy junk box cannot have too many capacitors. Let’s review from last month: Resistors impede, or “resist,” current flow in a circuit. Resistors don’t care if current flow is DC (direct current) or AC (alternating current). Resistors will resist either one equally well.

Capacitors, on the other hand, will block DC current. But under the right conditions, they will allow AC to flow Why? Capacitors are frequency dependent.

Caps are Frequency Dependent

Capacitors (“caps” in technician vernacular) will pass AC current under certain conditions. Physicists and electrical engineers call these “certain conditions” According to the Electronics Tutorials website: <>, “capacitive reactance of a capacitor decreases as the