I noticed a recent discussion about the use or deletion of the circuit tag. Is there value in using general tags in addition to specific tags that are often essentially sub-categories of the general tag? For instance in addition to the circuit tag, components, power, motor, transformer and capacitor are all tags that have more specific related tags.
There shouldn't be a circuit tag. It is a meta tag that can apply to a huge number of questions on this site, and is thus useless. All the others you mention are much narrower, with the possible exception of power.