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5W ophir 20C LPM by Offroad now + datalogging

offroadfreak8582

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Re: 5W ophir 20C laser power meter by Offroad

UPDATE:

So i got V3 finally ready! I also updated the OP with this:



This unit runs 2x 18650 for the display and datalogging. And 2x 9V for the ophir. Even then with all the capacity it is smaller then V2:











Here is a video review of the meter:


It was very hard to make the small cutout for the datalogging option with a dremel. But it worked out fine :D Also At first i had some problems with the analog signal wire on the smaller VGA adapter. The wire was to close to the + and - of the ophir. Which caused fluctuations. So i choose another pin to connect the signal wire to and now it runs great!

Greetings,,
 

Pman

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Re: 5W ophir 20C laser power meter by Offroad

Gotta love it! Great tutorial and info, here.
Glad I was able to +Rep you again.
Also, nospins info, is a great addition for all of us (allready repped you):).
Finding myself printing out all additional info. so I can have a hard copy to look over rather than having to search all over for related info. on things.
 
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Bob_Boyce

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Re: 5W ophir 20C laser power meter by Offroad

Had a hell of a day. Could not figure out why the new lpm kept fluctuating in readings whilst the ophir was not even connected. And it was wired the same as the other lpm. Replaced a the 3PDT switch and recheck over recheck. What do you know. The VGA port i used in this build is smaller. Which means the analog signal of the ophir was closer to the cables that power the ophir. That caused interferance with the analog signal. So i chose another pin of the VGA cable and reconnected the VGA cable to the molex adapter. Now it workes fine :beer: Still gotta do some dremeling and some testing.

Also even though this build has four times the capacity of the previous build AND had an arduino inside it is smaller then the last build :beer:

Greetings,,
That is really odd considering that you're using a pair of 9V batteries to power the Ophir. I've seen this sort of thing when power supplies are used that have too much noise on the output power leads, not so much with batteries. There must be noise feeding back out of the Ophir head on the power supply rails that was coupling into the analog output lead. Keep in mind that these Ophir heads were never designed to be remoted like this. They were designed to be bolted to a heatsink and the factory supplied leads soldered directly to a PCB in a LPM. To remote one, you should really use seperate fully shielded wires for each of the power and output conductors with all shields securely bonded to case/earth ground. Even wiring inside of an LPM case should also be routed away from all sources of noise such as power supplies or digital electronics, or well shielded as well. It only takes a very small amount of noise coupled onto the Ophir output lead to affect readings.

Bob
 

offroadfreak8582

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Re: 5W ophir 20C laser power meter by Offroad

That is really odd considering that you're using a pair of 9V batteries to power the Ophir. I've seen this sort of thing when power supplies are used that have too much noise on the output power leads, not so much with batteries. There must be noise feeding back out of the Ophir head on the power supply rails that was coupling into the analog output lead. Keep in mind that these Ophir heads were never designed to be remoted like this. They were designed to be bolted to a heatsink and the factory supplied leads soldered directly to a PCB in a LPM. To remote one, you should really use seperate fully shielded wires for each of the power and output conductors with all shields securely bonded to case/earth ground. Even wiring inside of an LPM case should also be routed away from all sources of noise such as power supplies or digital electronics, or well shielded as well. It only takes a very small amount of noise coupled onto the Ophir output lead to affect readings.

Bob
Hey bob! You are completely right about the noise. It was the power cable that led to fluctuating readings. Now it is consistent. What i now found out is that the arduino is also causing fluctuations. Although they are very minor. I am isolating the arduino also asap. And i am re-routing/isolating the wires and see what i get. Now when i hook it up to my laptop. And hit the sensor with a 3100mW 445 the display fluctuates about 10mW sometimes with the datalogging reading. Sometimes even more at that power. So i am going to try to get a "less noisy" ready when the arduino is ativated.

Thanks :beer:
 

Pman

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So is part of the problem where the Arduino is mounted? See what happens when it is isolated/seperate from enclosure. Assuming it doesn't fluctuate 10mw with a low powered unit...
 

offroadfreak8582

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So is part of the problem where the Arduino is mounted? See what happens when it is isolated/seperate from enclosure. Assuming it doesn't fluctuate 10mw with a low powered unit...
No on a low powered unit it only fluctuates 1-2mW. Will do some testing later on to see if i can improve accuracy with high powered handhelds. I think the main problem is the signal wire from the display needs to be isolated as it runs under the arduino.

Greetings,,
 

lilcomposer

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I can't find a price...did I miss it? I would to have such a fine instrument.
 




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