Capacitors C1, C2 and C3 are accompanied on this schematic by a semicircle, square and triangle symbol respectively. I'd expect the meaning of unusual symbols to be explained on the same drawing; they aren't, so perhaps they belong to a convention I've not yet encountered.

enter image description here

Link to source of schematic

Edit: Encountered these same symbols on a capacitor in the Heathkit IM-58 Harmonic Distortion Meter [though the symbols don't appear in the schematic]: enter image description here

  • \$\begingroup\$ You should link to the source of the diagram and take note; this isn't a well drawn diagram so don't expect logic in the symbols. \$\endgroup\$
    – Andy aka
    Jan 1, 2022 at 11:55

1 Answer 1


These are multiple electrolytic capacitors in a single package. The package would have more than the usual 2 pins, one for each capacitor and a shared ground pin. Each non-ground pin would have such a symbol next to it to identify it. The markings on the side would then state the symbols and their respective capacitances/voltages.

Here's a picture of such a capacitor. (Source: Myself).

Multiple capacitors in single package

  • 3
    \$\begingroup\$ You will probably also find these symbols stamped on the terminals themselves if you look at the base of the capacitor. I'll try to find a photo. \$\endgroup\$
    – user16324
    Jan 1, 2022 at 15:35
  • \$\begingroup\$ As it happens, I finally did! [Edited question to show findings]. \$\endgroup\$
    – Simon Owen
    Feb 20, 2022 at 8:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.