Power, Voltage, Current Supplies

power supply

I am confused by the use of these three terms in conjugation with supplies.

I read somewhere that the prime objective of the circuit is to provide power rather than voltage? What exactly does that mean. Isn't \$Power = IV\$? So saying that you're supplying power rather than voltage is another way of saying supplying a large current. If so why not just say so. Why beat around the bush when saying a current supply is far more intuitive than a power supply?

So what does this cryptic sentence mean: "Supplying power to the load." Do they mean a large current or a large voltage?

Best Answer

In general, the term "voltage supply" refers to a constant voltage supply, and "current supply" (or "current driver") refers to a constant current supply. Both are power supplies, they just try to regulate different things.

Typically* "supplying power to the load" means supplying the voltage that the load is rated for, and letting it draw whatever current it wishes or intrinsically does. It doesn't have to be a large voltage or current, but the point is to supply energy, instead of communicating by sending a signal, which usually involves only a tiny current.

*It's also a pretty vague saying that could refer to something different than what I wrote above.