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WTB: LPM with fast response (Ophir?) sensor.

DTR

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I know what you meant. It is called a panel meeter.;)
 





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Thanks DTR ;)

I forgot to put an E, more in meeter, maybe someday I will learn to write English correctly haha,
 
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Can you link me? "NOS Ophir" didn't do me any good as a search term.

NOS=New Old Stock... :crackup:
The heads were actually New Surplus unused heads.
DTR has the correct link for the new Calibrated ones..

The sensor should only be consuming a few milliamps.

-Trevor

What draws the majority of the current is the converter
if used and the LED DPM...
An LCD type would no doubt draw less current..

My fault, with "panel meter" I meant the red LCD voltmeter.

You are still correct.. It is a Digital Panel Meter (DPM) that
just happens to be a voltage measuring type...;)


Jerry
 
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rhd

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No... with that DPM you will get a resolution of 10mW...

How were you able to identify that? It didn't seem to specific resolution, unless I overlooked something.

When I saw that each digit had a decimal point LED next to it, I assumed that the display would have shown 3 digits of precision when measuring < 10V.

If that's not the case, I'll need to keep searching for a a volt meter readout. LED would be preferable. Presumably a 4 digit display with a voltage measurement range in the single digits would be appropriate.
 
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It's simple....
It is a full 4 Digit Display...
The specs for that DPM state a maximum display of 33Volts
It takes at least 2 of the 4 digits to display 33..... or 32

Then there are 2 digits left.... 32.XX is all you get...
Accuracy is stated at 1 digit....
That is a resolution of 10mV....


Jerry
 
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DTR

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The panel meeter draws 90mA. So that leaves 40mA being drawn by the head and the converters. I prefer the LED as it is much better for making LPM videos for my tutorials or customers.

Here is the one I ordered. If you get something similar read the description carefully they have ones that look identical but some don't have the same resolution or range.;)
This is a 20V range with 1mV resolution.
4 1/2 Digital DC20V Voltage Panel Meter Voltmeter | eBay



Here is a diagram 300EVIL over @ PL made for me. You can use 2 9V batteries instead of four like the picture or you can replace them with two 12V out DC-DC converters as I did. :beer:
OphirMeterWiring.jpg
 
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rhd

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It's simple....
It is a full 4 Digit Display...
The specs for that DPM state a maximum display of 33Volts
It takes at least 2 of the 4 digits to display 33..... or 32

Then there are 2 digits left.... 32.XX is all you get...
Accuracy is stated at 1 digit....
That is a resolution of 10mV....

Thanks Jerry

I (perhaps incorrectly) assumed that the presence of 4 decimal points indicated that in the 0-9 V range, the display would scale to show 1mW resolution. IE, 1.532 volts, could show as such (the display itself appears capable of that) But I suppose that with cheap chinese stuff, it's unwise to make such assumptions.

The panel meeter draws 90mA. So that leaves 40mA being drawn by the head and the converters. I prefer the LED as it is much better for making LPM videos for my tutorials or customers.

Here is the one I ordered. If you get something similar read the description carefully they have ones that look identical but some don't have the same resolution or range.;)
This is a 20V range with 1mV resolution.
4 1/2 Digital DC20V Voltage Panel Meter Voltmeter | eBay

Here is a diagram 300EVIL over @ PL made for me. You can use 2 9V batteries instead of four like the picture or you can replace them with two 12V out DC-DC converters as I did. :beer:
OphirMeterWiring.jpg

Thanks DTR, that's really helpful.

Am I misinterpreting the schematic, or does that have 36V (4x 9V batteries in series) connected to the LPM head?
 
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LaZeRz

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Thanks Jerry

I (perhaps incorrectly) assumed that the presence of 4 decimal points indicated that in the 0-9 V range, the display would scale to show 1mW resolution. IE, 1.532 volts, could show as such (the display itself appears capable of that) But I suppose that with cheap chinese stuff, it's unwise to make such assumptions.



Thanks DTR, that's really helpful.

Am I misinterpreting the schematic, or does that have 36V (4x 9V batteries in series) connected to the LPM head?

2 Batts in parallel and 2 in series (read it wrong)
 
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DTR

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Thanks DTR, that's really helpful.

Am I misinterpreting the schematic, or does that have 36V (4x 9V batteries in series) connected to the LPM head?

As I understand it. +18V and -18V.:beer:

Hi, I manage to locate this OPHIR head for slightly less, may I know if this is the same as the one above and can be used?

Ophir OEM Laser Power Meter Sensor for CO2 YAG 60W | eBay

It is not the same. That one is a 60W head Calabrated for CO2 or YAG lasers. The one I linked to is a 5W head that is designed for visible wavelengths.

They both may read visible wavelenght lasers but the 60W heads resolution is "Calibration: 0.1 Volts / Watt" 10mW resolution

And the 5W head is "The meter is calibrated 1 mV" 1mW resolution
 
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rhd

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As I understand it. +18V and -18V.:beer:

The eBay listing actually calls for:
"All you have to do is supply the power meter with +/- 15 volts, and a voltage is outputted in proportion to the laser power."
But 300Evil knows his shit, so I'm assuming the 18V figure is safe?

What did you use as a DC-DC converter?
 

DTR

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The eBay listing actually calls for:
"All you have to do is supply the power meter with +/- 15 volts, and a voltage is outputted in proportion to the laser power."
But 300Evil knows his shit, so I'm assuming the 18V figure is safe?

What did you use as a DC-DC converter?

Well at first I had it hooked up to two nine volt batteries for +9V and -9V and it worked just fine. The data sheet says "±5V to ±18V regulated".
http://www.ophiropt.com/laser/pdf/20C-SH_20C-A_20C-UAU.pdf
 
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rhd

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I'm going to take the plunge and grab one.

I've been searching for the last 20 or 25 minutes to find a similar LED panel in blue instead of red. I couldn't find one with the appropriate resolution. If anyone happens to have found one, know of a link, let me know. I'm going to place my order in ~30 minutes. Going to search for a nice housing first :)
 




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