Old 08-28-2007, 10:07 PM #1
rog8811's Avatar
Class 3B Laser
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
rog8811 rog8811 is offline
Class 3B Laser
rog8811's Avatar
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
Default Electronics help please

I want to drive 2 lasers from 3 transistor switched inputs, to give red only, green only and red & green together.

Could you cast you eye over the circuit below and tell me if it is a workable scheme please.

Regards rog8811
Attached Thumbnails
Electronics help please-3chan_to_2chan.jpg  


__________________
See all of my videos on Vimeo
http://www.vimeo.com/4454150

Lots of tutorials and information on lasers
http://www.rog8811.com/

In the land of the blind the one eyed man..... is most likely holding the laser
rog8811 is offline   Reply With Quote


















Old 08-29-2007, 12:40 AM #2
Hemlock_Mike's Avatar
Class 4 Laser
 
Join Date: Jan 2007
Location: North Iowa
Posts: 6,221
Rep Power: 111795
Hemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond repute
Hemlock_Mike Hemlock_Mike is online now
Class 4 Laser
Hemlock_Mike's Avatar
 
Join Date: Jan 2007
Location: North Iowa
Posts: 6,221
Rep Power: 111795
Hemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond reputeHemlock_Mike has a reputation beyond repute
Default Re: Electronics help please

Rog --

I would do the switching on the base side of the driver transisitosrs using this circuit and 1n4148 diodes. *Your design here adds another 0.7 volt drop to your LD's.
I assume you're using NPN transistors for drivers and it's more efficient to switch the low current parts.

Mike
__________________
Don't freeze yourself to cold steel
Hemlock_Mike is online now   Reply With Quote
Old 08-29-2007, 07:08 AM #3
rog8811's Avatar
Class 3B Laser
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
rog8811 rog8811 is offline
Class 3B Laser
rog8811's Avatar
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
Default Re: Electronics help please

Hi Mike, yes they are NPN transistors, I am adapting an existing circuit so I will need to look to see if I can put this the other side of them....The main thing is though that this looks a possibility.

Thanks for the response,
Regards rog8811
__________________
See all of my videos on Vimeo
http://www.vimeo.com/4454150

Lots of tutorials and information on lasers
http://www.rog8811.com/

In the land of the blind the one eyed man..... is most likely holding the laser
rog8811 is offline   Reply With Quote
Old 08-29-2007, 10:00 AM #4
Benm's Avatar
Class 4 Laser
 
Join Date: Aug 2007
Location: Netherlands
Posts: 7,623
Rep Power: 210024
Benm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond repute
Benm Benm is offline
Class 4 Laser
Benm's Avatar
 
Join Date: Aug 2007
Location: Netherlands
Posts: 7,623
Rep Power: 210024
Benm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond reputeBenm has a reputation beyond repute
Default Re: Electronics help please

What exactly are you connecting on the right hand side of that schematic?

If both devices are the same voltage (e.g. 5V powered laser modules), it would work fine. On the other hand, if one is a red laser diode, and the other is an IR pump diode, it would not work very well, because the IR diode has a lower drop voltage and would consume all the power coming from the middle input.
Benm is offline   Reply With Quote
Old 08-29-2007, 12:28 PM #5
rog8811's Avatar
Class 3B Laser
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
rog8811 rog8811 is offline
Class 3B Laser
rog8811's Avatar
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1251
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
Default Re: Electronics help please

@ Benm, thanks for the input, I must admit I had not considered that, I will need to have a look at my setup and check that out.

Regards rog8811
__________________
See all of my videos on Vimeo
http://www.vimeo.com/4454150

Lots of tutorials and information on lasers
http://www.rog8811.com/

In the land of the blind the one eyed man..... is most likely holding the laser
rog8811 is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 03:25 PM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC