what do you know that i dont about red diodes then?
why is it on my previous setups that when the diodes were mounted in one block all touching, adjusting one driver changed all the diodes?
Senior Member
what do you know that i dont about red diodes then?
why is it on my previous setups that when the diodes were mounted in one block all touching, adjusting one driver changed all the diodes?
Eat Sleep Lase Repeat
Senior Member
hi
anyone on here as far as i am aware, when they have built homemade laser setup
always isolate diodes from ground ya think with that many people doing it there is proberly a good reason for it, do some research and see what you come up with
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for a good time click here:
http://www.photonlexicon.com/forums/...rklight+series
Pat B
laserman532 on ebay
Been there, done that, got the t-shirt & selling it in a garage sale.
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thanks guys .
Eat Sleep Lase Repeat
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Originally Posted by andy_con
I mean to connect all the diode cases, the cathodes, to negative ground. And each anode goes to a separate driver, so you can control each diode separately (one may also put a small resistor of a few ohms in series to each diode and have them controlled by one single driver).hi
anyone on here as far as i am aware, when they have built homemade laser setup
always isolate diodes from ground ya think with that many people doing it there is proberly a good reason for it, do some research and see what you come up with
Obviously that won't work for the drivers that people often use here, where the anode of the diode goes to the plus supply; eg the die4drive. That's why I said with a decent driver that has the diode connected to ground, all this insulating effort can be avoided.
It is a much safer way to do, because otherwise the briefest short of the insulated case towards ground immediately kills the diode. There is even the phenomenon that the diode can be killed simply by having too a large capacitance of the insulated case against ground. I don't want to know how many diodes died because of this setup. I just wonder why ppl continue to build drivers that way....
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what
it works better the way we do it we are not going to all this trouble for nothing there is a valid reason they build the drivers like this and i am no electronics expert so i cant say why but i am sure are resident expert could chime in and explain it all robin or dr lava care to help out here
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Red, I have te utmost repect for you but in this case, I think you're confusing 'decent driver' with 'different type' of driver. For Anode case diodes, which are the majority of IR diodes, a cathode modulator type driver makes the most sense for safety and speed. This is why there is this class of driver. For case neutral diodes like most 405nm diodes, either cathode or anode drivers work fine. For red 5.6mm can diodes (cathode case), an anode driver makes the most sense, but properly isolating the diode and using a cathode driver works as well. It just so happens that cathode drivers are readily available and inexpensive, so many people choose to use them (myself included) to drive red diodes.
There will probably be pre-built anode drivers redaily available and inexpensive before too long, and there are even plans on the forum to build one. But until then, insulating works well and with the method shown capacitance is a non-issue.
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Allright, agreed ;-) I myself happen to have bad experiences with red diodes on the Thorlabs LD1255 driver, which drives the cathode, and no issues with the other kind of drivers.
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Still, that wouldn't be a task that's too difficult, right? Change out the N-type driver MOSFET for a P-type and invert the signal coming from the (normally cathode-type) driver circuit. Basically just turn the entire power totem pole upside down.
You're still going to need to insulate the diode heat sinks from the equipment ground, though.
Needs moar photons
use a separate PSU that doesn't tie the DC ground to the AC ground
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