[Septillion] and [Hugatry] have come up with a hack to manipulate a USB charger into becoming a variable voltage source. Their project QC2Control works with chargers that employ Quick Charge 2.0 ...

In his video [Afroman] describes how the LM317 can be used to regulate current rather than voltage to provide a constant current source under varying load. This can useful for a number of ...

If there are two resistors in series across a voltage source, then the circuit is a voltage divider. A voltage divider consisting of two \(500 Ω\) resistors is connected across a \(9V\) battery.