Kenometer laser power meter interest. LITE version *closed*

I BEG YOU DO NOT USE YOUR METERS UNTIL YOU HAVE ADDED THE 100uF AT LEAST!! YOU CAN KILL YOUR THERMOPILE.
we've had 3 die already.

Holy moly!!

Are you going to put them on mine before you ship it out?

Rob

Yes, I am adding the mod to ALL meters I've yet to assemble.

Xtrm2Rick said:

gues i need those cap's to since all the shops in my area sucks and wont sell stuff like that...

Click to expand...

I'll mail your caps out today.

As an addendum to my last PM, is there any preferred method for opening the case? I have 2 screws on the bottom which appear to secure the thermopile, so either it snaps together really tightly or there's screws hiding under the rubber feet?

Hey Guys....

I changed the Value of my 100uF electrotylics 1st mod to 470uF and it
seems to be even more stable..
After 20 minutes with the 100uF caps my Lite started going into the Neg
readings again..
I also added a 10uF to the DC/DC converter's Input...
It has been ON for over an hour now with a 2.5 Watt Laser on the Head
and it is Rock solid.. but the Head is warming up quite a bit from the 2.5
Watts on the sensor..

There is another problem... since I had 3 Lites here I noticed that
2 of them had the Meter and Display Ground on the wrong pin of
the Single DC/DC converter PS's Output going to the Sensor Head...
The Correct Ground pins are common on the Left and Right sides and
need no jumper between like I found mine..
The drawing below shows the correct Ground pins and the wrong ones..
(NOTE:- this is only for the single DC/DC converter... I haven't tested
the dual DC/DC converter setup)

Here is a drawing of my latest Mods that work... I tested the output
ripple on my Scope and the Ceramic caps seem to have no effect on
reducing the Ripple..

Hope this helps you guys with the problems...


@maxh... if you have the Black Case with the 4 Philips head silver
screws on the corners... Just remove the 4 screws and the cover
will come off. Be careful not to pull ant wires off...


Jerry

maxh said:

As an addendum to my last PM, is there any preferred method for opening the case? I have 2 screws on the bottom which appear to secure the thermopile, so either it snaps together really tightly or there's screws hiding under the rubber feet?

Click to expand...

The screws are indeed under teh feet.

Jerry, your dc/dc converter is different than everyone elses. They are more than welcome to add the capacitor indicated by you as it will only increase stability. Anything over 100uf is just gravy.

The ceramic caps are bypass caps.

BTW, I didn't come up with the fix, I'm not knowledgable enough.

Ken... there is nothing to bypass after you add the 470uF caps
There is no change to the output signal as seen on our Oscilloscope
with or without the smaller caps...
But it won't hurt anything to add them... just not necessary.. IMO...

Again... like I posted above...
I only tested the Single DC/DC converters in my LITES..

The other 2 piece DC/DC converter PSs may exhibit other characteristics
and maybe the smaller caps are required....


Jerry

Sorry for the double post...
But even with your latest Zero Offset circuit... I still can't
change the non-zero display value..
Does it not work because I have a single DC/DC converter...:thinking:
Does it actually work with the dual DC/DC converters...
Has anyone actually built it and is it working...:thinking:

Jerry

Jerry

it could very well be that it's cause there is only a single dc/dc converter in yours.. I actually have in my posession a meter that has the zero mod in it and it is fully functional.. I'll show you a video of it if you want.

On another subject. How long have you been keeping the output on the scope? Was it during that entire hour test or was it just for a short while?

Hi. Ken.

After reading your fix-plan, I wonder if I can fix after you and I worry about ruining my Kenometer lite without fixing. Because I don't have much electronic knowledge to differentiate or buy the part "Cap", so send me the exact cap please....

And I wish someone will upload the photo of fixed inside of Kenometer lite...

SHIN

Shin, if you would like you can mail it back to me and I will do the mod for you. Of I will be more than happy to mail the caps to you. I can even take a picture and send it along with the info you need and were the caps go.

Thank you. Ken.

Please send me the cap..and the photo of wiring..
I'll try myself.:yh:

I love my Kenometer lite.

SHIN

Kenom said:

Yes, I am adding the mod to ALL meters I've yet to assemble.



I'll mail your caps out today.

Click to expand...

Thanks Ken, and thanks for this fix i certainly dont want to blow up my precious meter

Hi. Ken.

After my office work, I disassembled Kenometer Lite at home.
There is tar-like material all over inside. So I can't disassemble the PCB further...
Please tell me the next step...

And I ordered "the cap" already. You don't need to send them.:yh:

Thank you.
SHIN

Kenom said:

it could very well be that it's cause there is only a single dc/dc converter in yours.. I actually have in my posession a meter that has the zero mod in it and it is fully functional.. I'll show you a video of it if you want.

On another subject. How long have you been keeping the output on the scope? Was it during that entire hour test or was it just for a short while?

Click to expand...

No need for a video... but thanks...

For the first test of 1 hour the scope was not on the Lite's DC/DC
converter output for the 1st 20-30 minutes.
Then as I was satisfied that the mW display readings were stable
I hooked in the scope for the balance of the test...

Why do you ask... did you find another problem...:thinking:

BTW... If the dual DC/DC converter setup works with your Zero Offset
circuit I would like to get them and install them into my Lites...

@ SHIN... the Black "tar like" material is Hot Glue... if you take a wide
flat bladed screwdriver you can very gently pry the parts off depending
on how generous the builder was with the Hot Glue...


Jerry