Electronic – Why does the circuit work with ceramic capacitors but not electrolytic

I was the one that asked that question. Here is my rudimentary understanding:

You attach capacitors across \$V_{CC}\$/GND to try to keep the voltage more constant. Under a DC circuit, a capacitor acts as an open circuit so there is no problem with shorting there. As your device is powered up (\$V_{CC}\$=5V), the capacitor is charged to capacity and waits until there is a change in the voltage between \$V_{CC}\$ and GND (\$V_{CC}\$=4.5V). At this point, the capacitor will discharge to try to bring the voltage back to the level of charge inside the capacitor (5V). This is called "smoothing" (or at least that is what I call it) because the change in voltage will be less pronounced.

Ultimately, the voltage will not ever return to 5V through a capacitor, rather the capacitor will discharge until the charge inside it is equal to the supply voltage (to an equilibrium). A similar mechanism is responsible for smoothing if \$V_{CC}\$ increases too far beyond its average (\$V_{CC}\$=5.5V perhaps).

As for why you need them, they are very important in high-speed digital and analog circuits. I can't imagine you would need one for an SN74195, but it can't hurt!

Let's see: We have name Jamicon printed on the capacitor as well as NP. A simple search of Jamicon capacitors brought me to the website of Jamicon Electronics Corporation. Going to Capacitor->Product search menu brings us to the search interface.

I don't see any NP series capacitors, so I went to advanced search and used voltage and capacitance as inputs. It didn't produce any relevant results (the TK series, which it produces isn't what we have, from the datasheet description), so I went back to the basic search and checked capacitor descriptions.

I noticed term bi-polar in some of them and downloaded datasheets for the first one I saw. As it so happened, the datasheet was for NK series capacitor. The datasheet showed a picture of capacitor with NP mark and had Non Polarity in big letters on the first page and Standard non polarity series for using in polarity reversal circuits. in description.

So I guess that the capacitor isn't polarized. Also note that it doesn't seem to have the traditional polarized stripe on the body.

I hope that the thought process explained here will help you in future searches for part descriptions.