The 555 is capable of sinking and sourcing up to 200mA, but it gets very hot when doing this on a 12v supply.
This white led driver circuit shows the maximum number of white LEDs that can be realistically driven from a 555 timer . The total current was limited to about 130mA as each LED is designed to pass about 17mA to 22mA maximum. A white LED drops a characteristic 3.2v to 3.6v and this means only 3 LEDs can be placed in series.
As you can see in the circuit diagram , this electronic project circuit require few external electronic parts and is capable to drive up to 48 white LEDs from a 12 volts DC power source , utilizing few electronic components .
