basic laser module power/signal questions

[ghosttrain]

EDIT: this is how it is

blue cable - power + (12VDC)
brown - power - (12VDC)

yellow - signal + (5V)
black - ignal - (5V)

[frostypaw]

That should be fine surely? The instructions on all the drivers I've seen suggest using a regulated supply to set the MOD voltage to various values as you set up

If you're overdriving then running at the full 5v MOD for a length of time might be risking the laser but otherwise why not?

The pointer-boys are all running CW CC drivers, often heatsinked for long duty cycles. Can't see why you couldn't with a bigger, probably better regulated power supply

[-bart-]

The chinese don't even try to make it less confusing, now do they ?

Blue and brown are usually (formally) used for 230 V mains (AC).
But they might use it for 12V DC input. They then say 12V+ and 12V-, which is confusing because they mean "connect to the minus terminal of the psu" which is ground, or gnd, not 12V-.

Yes, you can hook it up to a proper 12VDC supply. The modulation input can be tested by a second 5VDC supply modulated or not, and may draw anything from .1uA to 10mA.

Some units may even light up by connecting nothing to the modulation input, in that case be extra careful with connecting it to an arduino, it might just have a +12V pullup resistor at the input.

[VDX]

... it's a good idea not to drive the inputs directly from an Arduino, but through a driver/inverter IC - I'm mostly using 74HCT14, which can handle 5V or 3.3V (e.g. from a Due) as input and give a perfect +5V output with only one driver ... or inverted in polarity, when feeding through two driver stages.

I have several drivers (cheap chinese and proffessional too), which needs the input with reverse polarity - so +5V or not connected means laser is ON, while pulling the modulation pin to GND switches the laser OFF.

Another rissue is the max. possible modulation frequency - most cheapish drivers can only handle some ten kHz ... I'm designing my drivers for 1MHz for better pulse-handling and signal quality/stability, but I have some proffessional grade drivers too, which are good for up to 20MHz or an AOM for modulating a CW laser beam with up to 40MHz ...

Viktor

[norty303]

Can I ask how you know that the brown and blue are 12VDC?
If you'd have given that to me I'd have said it was a PSU and driver all in one, AC power (blue-neutral, brown-live) and yellow-5V mod+ black-mod grnd

[norty303]

DPSS lasers use AC do they? Did the guy you bought it off tell you that as well?

Could you perhaps have your understanding of that PSU board the wrong way around, and its actually converting AC to DC for powering the diode and TEC?


For the modulation, the current is irrelevant. Its voltage. If you use 5V it'll be on full.

[norty303]

The modulation input will pull as much current as it needs. So long as it can draw enough it will be fine.

The pump diode is unlikely to be AC. It is likely to be a current limited DC driver. You could theoretically drive it with a Flexmod or any other DI diode driver.

[norty303]

What power is the module?

[norty303]

That's because it's 230v AC like we said for the blue/brown

[norty303]

So it's working then?
Who was the seller?