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 ...

Another important concern is the balance of currents that flow in multiple strings. We know that two or three strings of LEDs will have different combined forward voltages. The LED driver will deliver ...

Light-emitting diodes (LEDs) are often used with a voltage source from a power-supply output voltage. The output voltage increases until the current through the LEDs reaches the value of the ...

Most commercial LED flashlightsuse three AAA or AA batteriesin series that produce 4.5V. The batteriesthen drive four white LEDs that connectin parallel. These LEDs can workat voltages as low as 2.7V ...

Most small-size color LCD displays today use white LEDs for backlighting. These systems usually involve handheld devices with an LED drive circuit powered by a battery whose output voltage varies over ...

A blast from the Elektor archives: this 1998 battery tester uses a simple LED display to reveal a battery’s true condition under load — even below 1 V.