I am looking at a datasheet for NJM2073 (dual low-voltage power amplifier). On the fourth page, there is a sample circuit; right at the V+ input there is a symbol that looks like a capacitor. However, it looks like it is shaded in. What is that?
-
3\$\begingroup\$ It's an electrolytic capacitor. \$\endgroup\$– Leon HellerApr 5, 2014 at 1:36
-
\$\begingroup\$ What @LeonHeller said. \$\endgroup\$– Connor WolfApr 5, 2014 at 1:51
-
2\$\begingroup\$ It is a Japanese electrolytic capacitor \$\endgroup\$– Peter BennettApr 5, 2014 at 2:14
-
2\$\begingroup\$ @PeterBennett A "Japanese electrolytic capacitor" is not the same thing as the symbol that Japanese use for a capacitor. A "Japanese electrolytic capacitor" is like referring to a component manufactured in Japan when this is just about different standards for representing components in a schematic. \$\endgroup\$– alexan_eApr 5, 2014 at 7:56
-
\$\begingroup\$ @alexan_e: Sorry - I should have used a smiley :-) \$\endgroup\$– Peter BennettApr 5, 2014 at 15:59
2 Answers
Intercontinental symbols for fixed capacitor from here:
and from http://www.learnabout-electronics.org:
and a very old one....
This is a polarized (electrolytic) capacitor
While all the schematic symbols used for capacitors will have two lines or a line and a curve in parallel, thus looking like a parallel-plate capacitor, the precise nature of these symbols varies across region. EIA (North American) practice uses a parallel-line-and-curve symbol for a non-polarized capacitor and adds a + polarity marker on the line side for polarized electrolytics, while IEC/EN (European) practice uses a two-line symbol for non-polarized capacitors and a line-and-box symbol with the box on the + side, along with the + sign for polarity, for polarized capacitors, and EIAJ (Japanese) practice is to use the shading/crosshatching between the two lines to denote polarity instead of the box, as they use the two-line symbol as well.
BTW: if you're wondering why the US uses the line-and-curve capacitor symbol, it's to avoid confusion with the parallel-lines symbol used for relay, and more importantly contactor, contacts in industrial electrical work (such as ladder logic diagrams and industrial wiring diagrams).