Pwm » History » Version 7

peteruithoven, 2013-03-05 23:07

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h1. PWM
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PWM stands for Pulse Width Modulation and is used to control the power of the laser. On the HPC3020 you will see a mA meter and a turn knob that will allow you to control the power of the laser by hand. With PWM the Laos board can take over this function, which allows for e.g. engraving of pictures or controlling the right power settings for certain materials. 
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h2. Example of enabled laser PWM
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To use the power control from the LAOS board, you need to connect the _laser PWM_ output (are we sure this shouldn't be connected to _exhaust enable_?) to the _ANALOG_ input of your power supply. On the LAOS board this is _J39_, together with _laser on_. You need to make a two wire cable with a 3 pin JST on one side, and a 4 pin JST on the other side.
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* Use a 470 ohm (how much watt?) pull-up resistor between +5V and analog in at the laser power supply side. 
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* "C" connects to the analog in pin (and resistor)
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* "E" connects to GND   
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(This image is slightly confusing because the 4 pin JST already contains 2 cables for the _laser on_ connection, right?) 
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h2. HPC3020 laser
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hpc side, very much a poc (a what?) (How do I recognize the analog input? The image doesn't really help)
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An alternative image of a power supply, could someone highlight the analog input?
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laos side
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h2. KIII laser
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