Voltage-to-current converter drives white LEDs


Posted on Jan 13, 2013

You sometimes need to drive a white LED from one 1.5V battery. Unfortunately, the forward voltage of a white LED is 3 to 4V. So, you would need a dc/dc converter to drive the LED from one battery. Using the simple circuit in Figure 1, you can drive one white LED or two series-connected green LEDs, using only a few components. The circuit is a voltage-to-current converter, which converts the battery voltage to a current that passes through the LED. You can adjust this current and, thus, the brightness of the LED, by varying resistor R3.






Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

electret mike amp
A SPECIAL INTERFACE Joystic ( 68HC11A1)
Lights-On Warning
DIY Single-Ended (SE) 6L6 / 5881 Tube Amplifier
Simple Metal Detector Circuit
70 Watt MOSFET Audio Amplifier
BINARY DECIMAL LED DISPLAY VERSIONS OF THE SIMPLE FREQUENCY COUNTER
Shield drive by the PGA204 / 205 configuration circuit



Top