Did i just convert my projector from TTL to analog?

Hey guys..
I was messing with my cheapo Chinese projector today trying to fix the blue leak.
I got a new module and what i think is a driver board. (the attached photo)
When i swapped the modules i tried to set the jumper the opposite way as what it was set before and suddenly i could dim the diodes from quickshow.
When i tried dimming them with the before it was just on / off..

So did i just make it analog? If i did, why didn't the company i bought it from set it as analog when i bought it?

Did i just raise the value of my projector by changing the jumper? :rolleyes:

Attachment 29592

Hardly a surprise. Which make/model of green modules was this?

I didnt get much info about it, its a 532 nm 200mW Green. The red is 650nm 500mW and blue is 445nm 500mW. So this is à common thing? Is it because they want to make more money analog projectors?
The modules seem to be nonames and looks quite dodgy but i got this 1200mw projector for about 500 USD so i guess i cant complain.

Quite nice surprise for me :)

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Originally Posted by db3306

why didn't the company i bought it from set it as analog when i bought it?

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You probably bought the TTL version.

The jumper gets set to analog if someone orders the more expensive analog unit :P

wow :D any other surprises i should know about?

Quote:

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Originally Posted by db3306

wow :D any other surprises i should know about?

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Yeah, the one where you now need to check Imax (Maximum Current) of each diode to make sure the analog side was correctly calibrated. Overdriven diodes are not happy diodes, and tend to expire early.

Shame on the other PLers for not informing you of this.

Steve

Thanx Steve, i guess it could a good thing to do. Is there any tutorial around here for doing it?

Dennis

Find the output series resistor that feeds the diode, switch the PSU back to TTL and activate the laser, measure the 'voltage' across the resistor, switch the PSU back to analogue and feed the modulation input with 5vdc, re-check the voltage across the resistor.

The voltage should be the same as when running TTL - report your findings back here.

Hi Doc, thanx for you reply.
I could only find one resistor on the board for the laser so i suppose its this one?
I uploaded a photo, however this one is solded so tight that i can only measure on one side of it, do you think its possible to measure on this side and then find the negative pole on the cable that is going to the laserhead?

Cheers
Dennis

Attachment 29671

Quote:

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Originally Posted by db3306

Hi Doc, thanx for you reply.
I could only find one resistor on the board for the laser so i suppose its this one?
I uploaded a photo, however this one is solded so tight that i can only measure on one side of it, do you think its possible to measure on this side and then find the negative pole on the cable that is going to the laserhead?

Cheers
Dennis

Attachment 29671

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Yes, just follow the trace to the connector