An ammeter is always connected in series with the component whose current you want to measure. This means it is placed ...

The simplest complete circuit is a piece of wire from one end of a battery to the other. An electric current can flow in the wire from one end of the battery to the other, but nothing useful happens.

Linear constantcurrent drivers, for instance, offer low EMI, low cost, and use only a few components. Many designers favor them for low-current applications where power loss is a minor concern. If ...