Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers
Buy Site Supporter Role (remove some ads) | LPF Donations
Links below open in new window
FrozenGate by Avery
M140 post-mortem: Was this driver a bad choice?
- Thread starter jameadows
- Start date
@madmike8:
Yes, that schematic describes how I've wired the driver. The cap is 47uf/63V, just something I found in my scrap box, wired close to the driver module. I've got the whole thing mounted onto a large heat sink, probably overkill but it all fit together nicely:
Sorry for the poor focus, my phone camera is having a problem with close focus lately.
Picengrave looks pretty interesting from a quick glance, I'll take a closer look when I get a chance, thanks for the lead.
Cheers,
Joe
Yes, that schematic describes how I've wired the driver. The cap is 47uf/63V, just something I found in my scrap box, wired close to the driver module. I've got the whole thing mounted onto a large heat sink, probably overkill but it all fit together nicely:
Sorry for the poor focus, my phone camera is having a problem with close focus lately.
Picengrave looks pretty interesting from a quick glance, I'll take a closer look when I get a chance, thanks for the lead.
Cheers,
Joe
Attachments
I'd be interested to hear how that works out if you try it
There's a PDF doc on the PicEngrave site that shows a cool option using a Maxim digital potentiomter. I might try that one out when I get the chance.
- Joined
- Aug 14, 2013
- Messages
- 2,640
- Points
- 63
That would vary the voltage. You need something that varies the current.
- Joined
- Aug 14, 2013
- Messages
- 2,640
- Points
- 63
Should work fine then, as long as the driver's input is high impedance
What a great site!
My experience was very similar to jameadows. Home brew LM350 driver on bench worked fine. I then bought a 2A driver with TTL modulation, also to drive from CNC. All set up on bench and working fine. I then had the great idea of keeping all the electronics adjacent to my PC and CNC driver circuitry and running 6 feet of wire to the LDR..... New M140 ordered.
I assume it was the length of cable that caused its demise?
John
My experience was very similar to jameadows. Home brew LM350 driver on bench worked fine. I then bought a 2A driver with TTL modulation, also to drive from CNC. All set up on bench and working fine. I then had the great idea of keeping all the electronics adjacent to my PC and CNC driver circuitry and running 6 feet of wire to the LDR..... New M140 ordered.
I assume it was the length of cable that caused its demise?
John
LarryDFW
0
- Joined
- Dec 6, 2008
- Messages
- 1,581
- Points
- 63
The electronics may not have been the problem . . .
Did you have the black heat sink on the laser diode when you were testing it ??
If not, it could have been overheating that caused the demise.
Even your current setup with metal clamps is not ideal . .
LarryDFW
Did you have the black heat sink on the laser diode when you were testing it ??
If not, it could have been overheating that caused the demise.
Even your current setup with metal clamps is not ideal . .
LarryDFW
Last edited:
- Joined
- Aug 14, 2013
- Messages
- 2,640
- Points
- 63
6ft, wow. That would have several
microhenries of inductance at the bare
minimum. Couple that with the self
capacitance and it makes a pretty good
recipe for diode death. The driver should
always be as close to the diode as
possible. If they have to be separated by
more than a few inches, then some
oscilloscope testing is in order. That is
not to say that it could have been
something else. We can't rule out all
possibilities here, and there are many
possibilities. We don't know what driver
you are using.
This should have its own thread, BTW. Next
time start a new thread.
microhenries of inductance at the bare
minimum. Couple that with the self
capacitance and it makes a pretty good
recipe for diode death. The driver should
always be as close to the diode as
possible. If they have to be separated by
more than a few inches, then some
oscilloscope testing is in order. That is
not to say that it could have been
something else. We can't rule out all
possibilities here, and there are many
possibilities. We don't know what driver
you are using.
This should have its own thread, BTW. Next
time start a new thread.
Last edited:
That could have been a factor in my case, and also that I'd wired everything together with alligator clips, so there may have been some sporadic connections. After making a clean build it has been working reliably with the same driver. The driver is mounted on the heatsink near the LD. The power cord is about six feet long so I put a filter cap on the power inputs of the driver.
Cheers,
Joe