PWM with small transistor

211

02:46:23

Pulse Width Modulation of a big load with parts that can't break a large enough current.
When the square-pulse oscillator turns the transistor on it sinks the current to GND removing it from the heavier load (represented by the LED). The current going through the load is inverse to the pulsewidth.

published 12 years ago

pip

12 years ago

Not sure if i understand what you mean. Do you mean power dissipation in the switch as it's seeing 30ma and 20v just not at the same time the led sees 20ma at 5v not at the same time.

Karlberg

12 years ago

Hmm .. dunno. I mean the current takes the path of least resistance. When the transistor is on that's the path of least resistance. When the transistor is off the load is path of least resistance. Does that make more sense?

gijimodo

12 years ago

Nice. Gonna add this to my toolbox :)

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