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By increasing the current 25% and turning a LED on for 25% of the time, produces the same brightness as a constant current but draws less than 50% of the current.
It is a stupid circuit because it has nothing to limit the current so the LEDs will blow up.
The transistors amplify the current:
1) The current from the 555 into the base of the 2N2222 transistor is limited by the 1k resistor to about 5mA.
2) With a 5mA base current then the emitter current of the 2N2222 transistor is about 600mA.
3) With a 600mA base current then the collector current of the 2N3055 transistor is about 8A.
"With a 600mA base current then the collector current of the 2N3055 transistor is about 8A."
This is not true.
The current into the base of the 2N3055 is limited to the current taken by the load in the circuit under investigation.
Voodoo,
Please learn about PWM if you want by looking for Pulse-Width-Modulation in Google.
It is used for dimming lights and for DC motor speed controls.
No."With a 600mA base current then the collector current of the 2N3055 transistor is about 8A."
This is not true.
The current into the base of the 2N3055 is limited to the current taken by the load in the circuit under investigation.
Using a Hex schmitt trigger IC is no more involved than using a 555. And you don't have the wasted 10mA taken by the 555.