Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

Circuit providing constant current to LEDs

Probably everybody knows that LEDs don’t like current changes, so how to deal with this and avoid damages? One solution could be a circuit that provides a constant current despite variations of the input voltage.


For instance, this circuit can take up to 300mA and up to 40V and provide a voltage that is necessary for one LED. Circuit can be adapted for a single LED running from 3.5V or several LEDs like three connected in series. Then Circuit provides about 10V. More LEDs are used more heat is generated – heat sink is necessary in this case to avoid transistor overheats. This simple circuit is available as a kit for only $9.85. But probably it could be built quickly by electronics entrepreneur.  [Source]

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