DIY Laser Power Meter

[roSSco]

Can that display be set to drop off the . (point)??

So that it reads 000 instead of .000 or 174 instead of .174???



Thanks....

Just think of it as Watts and you're all set. So .200 = 200mW

 

[LarryQ]

Ahh...you are Correct Sir.....

Now how about turning off the "V"??..hehehehehe

What about your DIP switch settings with that meter?....

And the tap for the power???

Thanks for all the help!!!

Larry

 

[knimrod]

Hey Knimrod,

I PM'd you..but after thinking about it ..I thought that the info would be helpful to others.

Can you answer a couple of questions for me?

1) Can that display be set to drop off the . (point)??

So that it reads 000 instead of .000 or 174 instead of .174???

2) The 5 dip switches, What switch settings did you use on this display??

3) It's easy to see where you tap for the output to the meter, but where do you tap into the circuit to get the power for the meter??

At the +9V side of the power input and the GND,  where they connect to the board???

Thanks for the clarification.

Larry



Thanks....

Well, I haven't got my meter yet but I'm certain there's a way to turn the decimal point off. I assume it's the first 3 switches: 1,2,3 = off. If not, I'll figure out a way and let you know. However roSSco is correct that if you look at the power as "Watts", the decimal point has relevance.

Regarding the power for the meter, I would just run the meter's ground to the PCB ground and then tap the power (switched +9V) at the power switch terminal.

 

[turtlecannon]

Paypal Sent!

 

[roSSco]

The wires and instructions for that voltage panel were confusing. I'll post up how I wired it when I get home this evening.

 

[knimrod]

My meter showed up today.

A couple of things.  Be careful and double check everything.  The connector that came with my meter was wired backwards as the wire colors were all reversed in the connector according to the manual.  Not a big deal to fix, just pull the wires and reinstall in the correct order.  


The dip switch works as follows:

Positions 1-3 set the decimal place. If you want no decimal point, set 1-3 "off".  If you want a decimal point to the right  of the most significant digit, set 1 "on". 2 & 3 "off".
Position 4 selects the ground mode.  For a common ground (which is what we want) , set 4 "on".
Position 5 selects the meter resolution/range. Set 5 "off" for 1mV resolution (0-1.999V range) or set 5 "on" for a 100mV resolution (0-199.0V range)

So... for the meter to display as 0-1.999 Watts, set the dip sw.: 1=on, 2 & 3=off, 4=on, & 5=off
for the meter to display as 0-1999 Milliwatts, set the dip sw.: 1-3=off, 4=on, 5=off


Here's how the connector should be wired (top to bottom):

(1) O - Red ----------- Switched Battery 9V+
(2) O - Black --------- Ground (Battery)
(3) O - Blue ---------- Amp Signal +
(4) O - Green -------- Amp Signal -

This can be a 3-wire hook-up if you hook pins 2 & 4 together (black and green) and connect to the amp out- , pin 3 (blue)to the amp out+, and pin 1 (red) to the switched 9V battery + on the toggle switch.

This meter and back light draw about 30mA which will be fairly easy on the batteries.

I was also able to remove the "V" which appeared to be silk screened on the display by gently scraping it off with the end of a steel rule. I then applied some dry transfer lettering to indicate the appropriate units.

 

[chimo]

Great jobs rossco and knimrod! Looking forward to getting mine. I may use your schematic and try to shrink the board to surface mount (if I get energetic and can find the time). Cheers,

Paul

 

[roSSco]

My meter showed up today.

A couple of things. Be careful and double check everything. The connector that came with my meter was wired backwards as the wire colors were all reversed in the connector according to the manual. Not a big deal to fix, just pull the wires and reinstall in the correct order.


The dip switch works as follows:

Positions 1-3 set the decimal place. If you want no decimal point, set 1-3 "off". If you want a decimal point to the right of the most significant digit, set 1 "on". 2 & 3 "off".
Position 4 selects the ground mode. For a common ground (which is what we want) , set 4 "on".
Position 5 selects the meter resolution/range. Set 5 "off" for 1mV resolution (0-1.999V range) or set 5 "on" for a 100mV resolution (0-199.0V range)

So... for the meter to display as 0-1.999 Watts, set the dip sw.: 1=on, 2 & 3=off, 4=on, & 5=off
for the meter to display as 0-1999 Milliwatts, set the dip sw.: 1-3=off, 4=on, 5=off


Here's how the connector should be wired (top to bottom):

(1) O - Red ----------- Switched Battery 9V+
(2) O - Black --------- Ground (Battery)
(3) O - Blue ---------- Amp Signal +
(4) O - Green -------- Amp Signal -

This can be a 3-wire hook-up if you hook pins 2 & 4 together (black and green) and connect to the amp out- , pin 3 (blue)to the amp out+, and pin 1 (red) to the switched 9V battery + on the toggle switch.

This meter and back light draw about 30mA which will be fairly easy on the batteries.

I was also able to remove the "V" which appeared to be silk screened on the display by gently scraping it off with the end of a steel rule. I then applied some dry transfer lettering to indicate the appropriate units.

That's what I was going to do this evening. ;D

I would suggest folks follow the 1234 vs. the color of the wires though. As he said the color codes are all screwed up.

 

[roSSco]

roSSco,

I'm in Perth Western Australia. I think I would like to grab 2 of these if I can. I really appreciate your help mate

I haven't checked USPS yet but I did check UPS and FedEx and they were both around $160.00

I'll get back to ya after I check USPS.

 

[roSSco]

[quote author=positron link=1200112201/135#141 date=1202117889]roSSco,

I'm in Perth Western Australia. I think I would like to grab 2 of these if I can. I really appreciate your help mate

I haven't checked USPS yet but I did check UPS and FedEx and they were both around $160.00

I'll get back to ya after I check USPS. [/quote]

USPS to the rescue! ;D

PM me if you are still interested in doing this.

 

[toked323]

heyh knimrod what is the over all estimated price? and any picts of the circuit board only ?

thanks,
toked

 

[roSSco]

heyh knimrod what is the over all estimated price? and any picts of the circuit board only ?

thanks,
toked

http://www.laserpointerforums.com/forumdata/yabbfiles/Attachments/DSCF0795.JPG

 

[amkdeath]

very nice, can wait to assemble mine!

BTW, where does the GND on the PCB get connected to??

 

[knimrod]

heyh knimrod what is the over all estimated price? and any picts of the circuit board only ?

thanks,
toked

Pictures are scattered throughout this thread..

Overall price?  Lessee....

Coherent sensor assy: $35.
LPF Amp PCB: $8.
Enclosure (RS) :  $4.
Amp. components (RS): $10.
Misc.: $3.
DPM: $20.-$25. (optional)

Total: $60-$85.

You can do it for more or less depending on what you already have on hand.  The cheapest way to build this is without the dedicated panel meter and to just use your multimeter.  When the sensor assembly was $25., that was a $50. project.

Anyway you slice it, it's a bargain at twice the price.

 

[amkdeath]

[quote author=toked323 link=1200112201/150#154 date=1202177437]heyh knimrod what is the over all estimated price? and any picts of the circuit board only ?

thanks,
toked

Pictures are scattered throughout this thread..

Overall price?  Lessee....

Coherent sensor assy: $35.
LPF Amp PCB: $8.
Enclosure (RS) :  $4.
Amp. components (RS): $10.
Misc.: $3.
DPM: $20.-$25. (optional)

Total: $60-$85.

You can do it for more or less depending on what you already have on hand.  The cheapest way to build this is without the dedicated panel meter and to just use your multimeter.  When the sensor assembly was $25., that was a $50. project.

Anyway you slice it, it's a bargain at twice the price.
[/quote]


whats the shipping on those DPM's man?? last I checked the DPM itself was 9.99 before shipping

 

[knimrod]

very nice, can wait to assemble mine!

BTW, where does the GND on the PCB get connected to??

The ground would be connected to the common connection of the batteries. The batteries are in series so a red (+) wire from one battery would be connected to the black (-) wire from the other battery and this becomes the "ground" or "common" for the amp PCB and the "Power-" for the DPM. The other red (+) wire from the battery pair is the unswitched +9V which should go to one power switch pole, and the other black (-) wire from the battery pair is the unswitched -9V which should go to the other power switch pole. The switched +9V from the power switch is then connected to the amp +9V input and to the DPM "Power+". The switched -9V from the power switch only goes to the amp -9V input.

This battery connections are detailed in the schematic but this description should help a bit.