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Show"N"Tell ( Your Machines) / Re: The Laser Project.
« on: November 28, 2010, 03:30:42 AM »
Hi Guys,
At the risk of being totally boring, thought you may be interested in these little rotary encoders. They are low cost pulse generators which could be considered as the poor man’s MPG (light duty only) and their main field of usage is for the volume control / on off switch for vehicle and domestic audio systems. They output a 2 bit gray code which by comparing the current pulse with the previous pulse enables the direction of rotation to be established (for clockwise rotation the low order bit of the previous value always equals the high order bit of the new value whereas for anticlockwise rotation it never does).
The ones I am using output 20 pulses per revolution and are just ideal to set my PWM to any value between 0% and 100% in just 5 turns. The original concept was to use a multiturn potentiometer feeding an analog to digital converter but this little chap is all digital and simplifies things considerably. (pics show 10% and 90% PWM).
I was originally intending to have the PRF switchable between just 5kHz and 10kHz but I may just use another of these encoders to allow any setting between say 1kHz and 20kHz and limit the PWM accordingly (have to check the Synrad specification to see if this is allowable).
Tweakie.
At the risk of being totally boring, thought you may be interested in these little rotary encoders. They are low cost pulse generators which could be considered as the poor man’s MPG (light duty only) and their main field of usage is for the volume control / on off switch for vehicle and domestic audio systems. They output a 2 bit gray code which by comparing the current pulse with the previous pulse enables the direction of rotation to be established (for clockwise rotation the low order bit of the previous value always equals the high order bit of the new value whereas for anticlockwise rotation it never does).
The ones I am using output 20 pulses per revolution and are just ideal to set my PWM to any value between 0% and 100% in just 5 turns. The original concept was to use a multiturn potentiometer feeding an analog to digital converter but this little chap is all digital and simplifies things considerably. (pics show 10% and 90% PWM).
I was originally intending to have the PRF switchable between just 5kHz and 10kHz but I may just use another of these encoders to allow any setting between say 1kHz and 20kHz and limit the PWM accordingly (have to check the Synrad specification to see if this is allowable).
Tweakie.
