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Can I double up diodes on a single driver?






Pretty much the only way I'd trust running laser diodes would be in series (all components of a series circuit see the same current, no matter what)

But you must be sure that all the diodes are 100% electrically isolated from each other.

Boost drivers will probably not like the huge increase in forward voltage drop, but simple drivers like the LM317 can handle voltages up to 35v.
 
MarioMaster said:
Pretty much the only way I'd trust running laser diodes would be in series (all components of a series circuit see the same current, no matter what)

But you must be sure that all the diodes are 100% electrically isolated from each other.

Boost drivers will probably not like the huge increase in forward voltage drop, but simple drivers like the LM317 can handle voltages up to 35v.
Click to expand...
I second this.

It can also be done in parallel if you connect a low ohm resistor in series with each diode (5-10 ohm-ish). The amp-draw adds with each diode in parallel, the voltage stays. Series is still the best way though.
 
Do diodes die open most of the time or closed? I would be concerned about one diode dying and killing the other by taking on the full current.

Here is an link to a driver setup that is suposed to make doing this safer. I havn't read it yet but here you go.

laserbias
 
Yeah... but in that schematic each LD has its own current limiting
resistor being driven by the 5 Volt fixed Voltage Regulator...

Jerry
 
sightfx said:
Do diodes die open most of the time or closed? I would be concerned about one diode dying and killing the other by taking on the full current.

Here is an link to a driver setup that is suposed to make doing this safer. I havn't read it yet but here you go.

laserbias
Click to expand...
Red and IR diodes die closed, violet diodes might be 50/50... If you want to double violet diodes I suggest connecting them in series if you can.
 
Putting more than 1 diode on a driver is common over at PL for lab modules.

You just need to calculate a resistor to put on each diode.

Also, almost every time a diode dies, it dies close circuit, which means if anything it would draw more current and leave less for the other diodes. Failing open usually only happens from mechanical damage, or overpowering it by extreme amounts (A few amps)
 
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