Replacment Driver board for 15W laser
I've bought a 15w laser with driver board from E-bay (item number 322762195525) Unfortunately the laser is permanently on when only the power is connected to the controller board. The TTL is obviousley at 0 volts as noting is connected but the laser comes on.
My conclusion is that the controller board is faulty as without a signal on the TTL connection the laser should be off.
I've contacted the seller but by the tone of their reply this is going to be an up hill struggle, so in the mean time to stop me having a non usable laser I'm look to replace the controller so when I do finally get one or the cost from the e-bay sell I'll have a spear.
I'm in the UK so a local supplier would be best as delivery time should be quicker then from elsewhere, any advice appreciated.
@Andy_T Your assumption that the TTL is at 0 Volts may not be correct, if there's no connection then it will float due to electrical noise and that may be sufficient to enable the laser. To confirm connect the TTL input to GND and if it's still on then you have a problem.
If that's the case, forget communications with the seller and open an ebay case (same as a PayPal case), you will almost certainly win and get a refund.
If you've read any of these forums you'll know that there's no such diode as a 15W and it's just an over-driven 6W. If you measured the output it's probably not anywhere near 15W anyway but if it is, it won't be for long.
Thank you for the reply.
I know it isn't a true 15W but as that's how it's described I thought I'd do the same to keep in line with the seller description. Thank you for saying as if it wasn't something I knew I would have liked to have known.
I've tried grounding the connection but still get the same result mores the pity. I'll open a case but I'd still like to know if anyone sells a replacement driver board as having one on the shelf is never a bad thing.
@Andy_T The problem with replacing the driver is you need a bench power supply with current limiting to adjust it or you'll just instantly fry the diode.
Here's the method:
Connect the bench supply to the driver and slowly increase the current, while also adjusting the laser driver. Once it's set correctly you can use the normal unrestricted supply. I do this with the laser power meter to monitor the output, once you get 5.5W from the 6W diode that's where I stop.
@Zax Hi Zax,
Fortunately I do have such an item along with a whole bunch of other electronics testing and measuring devices such as oscilloscopes ....... Thank you for the advice much appreciated.