Oft asked if non-polar film caps have orientation, the answer is very clear. Yes! They do! So how does one tell the orientation of a film cap? Using an oscilloscope and your own fingers as an antenna, connect the shield and the positive leads of the scope probe to the leads of the film cap, and using your fingers, grip the capacitor and read the level on the scope. Reverse the leads and perform the same task. The orientation with the least amount of level on the scope is the correct orientation, and should have the end connected to the shield of the probe marked as the shield or ground end.
Thanks for sharing. It is usually assumed that the outer foil contact should face low impedance side, that is, the source.
The outer foil of the capacitor towards the input of the speaker for example, or outer foil towards the chassis for decoupling for example. This is the same as orienting it towards the output of the amplifier, you are orienting it towards the lowest impedance point.
The V-Caps have an explanation for their installation, I only have experience with them;
| CuTF & TFTF Series |
|---|
| * The green lead indicates the outermost foil, and should be connected to the lowest impedance path to ground. Another way to identify outer foil is the writing on the label flows towards the outer foil. |
- Use a quality wire stripper when removing the insulation, like a Klein No. 11055
- When used in amplifiers, outer foil should be connected towards the plate of first stage
- If using as a bypass cap to ground, connect green lead to ground.
- If using as a bypass cap from a signal to B+, connect green lead to B+.
- If using in a feedback position, connect green lead towards the output
- When securing near objects or circuit traces that have sharp edges, Silicone tape can work well as a buffer, to prevent laceration of the V-Cap’s outer skin.|
1 Like