Running multiple diodes from a single drive via parallel connections.

[gizmoguy]

According to that data sheet, minimum 3.7, maximum 5.5 VDC. Diodes can require slightly different voltage from one to the other, even if the same model number, but a driver set to what ever current you have decided to run it at will automatically adjust the voltage so the diode draws the amount of current you set it for, so in that case, as long as you have enough voltage from your batteries and it isn't too much voltage for the driver, you don't need to concern yourself with it, with the following exception:

If the battery voltage is close to depletion, or even full charge for that matter, and that amount of voltage is too close to the amount required for the diode, your laser might have reduced output, or quit putting out light before the batteries are discharged through their full capacity, or only discharged half way. i.e., if your laser diode required 4.0 VDC for full output and the driver itself adds or drops an additional .2 volts, or two tenths of a volt, and your battery was only producing 4.0 VDC, then there wouldn't be enough voltage to drive the diode to full output power because it would only receive 3.8 VDC. I'm writing about a BUCK driver, not a boost, for boost drivers it's a whole different ball game.

Thanks a lot Alaskan appreciate the help.

 

[FireMyLaser]

According to that data sheet, minimum 3.7, maximum 5.5 VDC. Diodes can require slightly different voltage from one to the other, even if the same model number, but a driver set to what ever current you have decided to run it at will automatically adjust the voltage so the diode draws the amount of current you set it for, so in that case, as long as you have enough voltage from your batteries and it isn't too much voltage for the driver, you don't need to concern yourself with it, with the following exception:

If the battery voltage is close to depletion, or even full charge for that matter, and that amount of voltage is too close to the amount required for the diode, your laser might have reduced output, or quit putting out light before the batteries are discharged through their full capacity, or only discharged half way. i.e., if your laser diode required 4.0 VDC for full output and the driver itself adds or drops an additional .2 volts, or two tenths of a volt, and your battery was only producing 4.0 VDC, then there wouldn't be enough voltage to drive the diode to full output power because it would only receive 3.8 VDC. I'm writing about a BUCK driver, not a boost, for boost drivers it's a whole different ball game.

When driving a diode that has very similar/overlapping voltage range as the battery, than you need to use a buck-boost driver to avoid this issue.

But since he intends to drive several diodes in series, I recommend using a simply boost driver.

One thing to take note of, is that when you use two diodes in series on a boost driver, the input current will be double that of when driving just one diode.
When picking a driver, you most know it's maximum rated input current, min/max input and output voltage, min/max output current, and maximum output power.

When driving many series diodes, you will exceed the maximum input current very quickly, so to get around that you will need to use a higher input voltage.
Maybe 2 or 3 batteries in series, depending on the application.

Knowing the driver's rated limits is the key to this.

 

[gizmoguy]

When driving a diode that has very similar/overlapping voltage range as the battery, than you need to use a buck-boost driver to avoid this issue.

But since he intends to drive several diodes in series, I recommend using a simply boost driver.

One thing to take note of, is that when you use two diodes in series on a boost driver, the input current will be double that of when driving just one diode.
When picking a driver, you most know it's maximum rated input current, min/max input and output voltage, min/max output current, and maximum output power.

When driving many series diodes, you will exceed the maximum input current very quickly, so to get around that you will need to use a higher input voltage.
Maybe 2 or 3 batteries in series, depending on the application.

Knowing the driver's rated limits is the key to this.

Alright thanks right now im in the process of making a custom host for them And researching the best way to heatsink them. whether that be with aluminum or copper or a combination of both.
After that im going to upgrade the lens to non acrylic and then try to find a driver that will be able to drive all 5 of the diodes if I cant i'm going to have to run each one separately.