Sudden change of power settings

Hardware settings, adjustments and fixes and other hardware discussion. This includes the "doHICky" Laser Power measurement system by Russ.
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Martín Lázaro
Posts: 89
Joined: Mon Aug 01, 2016 10:32 am
Location: Olavarria
Country: Argentina
Laser Machine Make or Type: Goldenlaser 2 fixed heads retrofited (6442s)
Laser Power: 80w + 50w
Laser Bed Size: 1300*600mm
Home Position: TL
RDWorks Version: 8.01.23
Accessories: rotary chuck
wireless panel
Windows Version: w7 64bits

Sudden change of power settings

Post by Martín Lázaro » Mon Dec 19, 2016 7:59 am

A week ago, i runed a job with two layers, the first layer at 50mm/s at minimum power to mark a line, and the second to cut the outside of a figure
The first layer dont mark anything, just moved the laser head, while i tried to understand, the second layer cuted the material ok. Then is not water protect, not glass tube, mmm
Yesterday, with a friend, we dismount the controller (6442s)
We identified and understanded a couple of circuits, to finish in two blue trimpots (preset potentiometers) that control the analog output of laser 1 and laser 2
Both analog outputs (with a job with one layer at 100% of power) show 3vcc and 3,77 vcc, strange.
Strange because they should show 5vcc, not 3 and why different voltages ?
We realized that this trimpots are not in a correct values, we dont know why. Then my friend pressed a little one of them and suddenly the oscilloscope showed 5vcc !!! Doing the same with the other we get the same result.
Then if you have a strange behavior, suddenly with the power settings and the results, and you are shure is not a bad power supply or bad glass tube, just disconnect the analog output of controller, run a job with 100% of power and you should get 5vcc, if is not in this way, maybe this trimpots are doing strange things like in my controller

Note :
I choose control the power with the analog output instead the PWM because i read this recommendation from chinese vendors, and have sense because if you use PWM and i change the frequency of laser, the power supply need to know this frequency to filter the signal, but the controller dont have a way to tell this value to the power supply. The signal of "Lon" that some chinese laser named "clock" is just a signal of 0vcc or 5vcc to allow the power supply output, is not a real clock

Choosing PWM you have some advantages, the most important, a higher velocity of change of power output, for example for 3d engraving.
The analog output use the same PWM (the processsor generate just one PWM signal to control both output signals) but with a second stage (resistors, capacitors and operationals amplifiers) to convert in a real analog output, with the disadvantage of lower velocity because this convertion method have lower times of response

Well, i hope this help someone in some moment
Martín.-
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Dustin Hawkinson
Posts: 158
Joined: Sat Nov 19, 2016 6:55 pm
Location: Phoenix, AZ USA

Re: Sudden change of power settings

Post by Dustin Hawkinson » Mon Dec 19, 2016 12:31 pm

Very interesting. Does using the analog output put practical limits on the speed you can scan/engrave at?
40W (ebay 50W blue wonder), 300mm x 500m, TL
Windows10 RDW 8.01.19
(The member formerly known as astral)
-Dustin

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Gene Uselman
Posts: 1316
Joined: Thu Jul 07, 2016 3:18 pm
Location: Suburban Minneapolis, Minnesota, US
Country: USA
Nickname: Gene
Laser Machine Make or Type: QC1390
Laser Power: 130W EFR
Laser Bed Size: 36x49
Home Position: TR
RDWorks Version: V8.01.19 LO
Accessories: I have a combining lens, pin tables [homebuilt], honeycomb table [LightObject], wireless remote on the way [crossed fingers]
Windows Version: Win 7 Pro

Re: Sudden change of power settings

Post by Gene Uselman » Mon Dec 19, 2016 5:15 pm

Kieth- I have a spare one of the same 6442S[EC] if you want to reverse engineer it for us? Great public service project now that the whole manual thing has been put to bed :twisted: Gene

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Keith Sherwin
Site Admin
Posts: 1593
Joined: Fri Jun 24, 2016 3:44 pm
Location: Heart of Canada
Country: Canada
Nickname: Keith
Laser Machine Make or Type: POS China
Laser Power: 80
Laser Bed Size: 400 x 600
Home Position: TL
RDWorks Version: V8.01.23
Accessories: Hot dog roller, doHICkey Power Meter, Multi-Lens, High power exhaust, Interior filter soon.
Windows Version: W7 Pro

Re: Sudden change of power settings

Post by Keith Sherwin » Mon Dec 19, 2016 6:44 pm

I believe the pot settings etc. have been discussed on another (LO) forum as well as the settings. I think your buddy Roger had a conversation with you about it in this forum or by PM.

No, I have enough work just screening potential members. EDIT: Passed that to another member

Then there is the updated manual for 8.01.21 - some changes there. Not really sure I have the energy or desire to do it again Amigo.
:idea: Started this forum.
Lead in creation of the RDWorksLab English Manual.
Cheers, :D
Keith

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