Custom high current drivers for 445s?

[jmgallego]

A lot of question are stated here as well as in other threads about 445 nm lasers.
@yobresal, I think max current is <1 A with a flexdrive. but with a micro boost you achieve more than 1 A. Eudaimonium said that on another thread.

I couldn't find where he mentions it. Does Eudaimonium says how to achieve more than 1A?

 

[Exerd]

I've been running a Flexdrive V5 for two days at over 1.2 AMP. It has no problem at all. I see no need for a Microboost if you want less than this.

You will of course need to configure the Flexdrive for its maximum output through the resistors.

 

[Elektrotechniker]

I've been running a Flexdrive V5 for two days at over 1.2 AMP. It has no problem at all. I see no need for a Microboost if you want less than this.

You will of course need to configure the Flexdrive for its maximum output through the resistors.

Thanks mate I have mine set at the highest range

 

[jmgallego]

I've been running a Flexdrive V5 for two days at over 1.2 AMP. It has no problem at all. I see no need for a Microboost if you want less than this.

You will of course need to configure the Flexdrive for its maximum output through the resistors.

In my case, I just want to test what is the max power of the 455nm diodes I have. Then build a lab bench version with a driver the would be able to deliver a range of up 2A. Based Kazer's tests, the "safe" limit is around 1.5A for continuous use.

And then, I will go back to regular business by bringing the current down to around 224mA (about 50mW), see if it really goes into single mode, try to take some holograms and, possibly, run more tests with iodine and bromine.

Jose

 

[Exerd]

I'm guessing by Friday that the Shark Buck 2A model I ordered will be here. I'm going to machine one of Jayrob's 18650 host pills flat and thermal epoxy the 2A driver down to it for a driver heat sink. I want to run up near 1.8A. My duty cycles are 10 seconds anyway. These diodes are going to be cheap enough to do stuff like this with them and not have to worry a great deal with killing them. I'm not made of money, but the hobby is interesting enough to where I don't mind pushing diodes extremely that are under $50.

 

[Kevlar]

Please post back with your results on the shark buck driver, I'm very interested.

 

[laser_freak]

A lot of question are stated here as well as in other threads about 445 nm lasers.
@yobresal, I think max current is <1 A with a flexdrive. but with a micro boost you achieve more than 1 A. Eudaimonium said that on another thread.

From the spec sheets for the 2 drivers:
Microboost drive: 0.065-1.0 amps
MicroFlex drive: 0.065-1.5 amps

Hope this helps

 

[Seoul_lasers]

What batteries do you use?

My guess is 2x 18650 Lion cells for 3.6v x 2 = 7.2v. These cells are 2.2 -2.6A/hr each Watch it, 18650s can give 4.2v each making 8.4v which might be a problem.

smaller cells will drain flat in no time. You need current if you are going to be running these new blues, either that or make a labby.

 

[Exerd]

smaller cells will drain flat in no time. You need current if you are going to be running these new blues, either that or make a labby.

Wattage is wattage, and it is energy. You can get wattage with volts or you can get wattage with amps.

Having more of amps or more of volts to make up the total energy will yield differing power profiles.

Say that a 4.5V diode is being driven off of an 18650. Its power profile will usually look more like a regressive curve from the start. As soon as the cell starts losing its small amount of voltage it has, the driver tries to make up for this by pulling more and more amps to meet the needed voltage and wattage requirement of the diode. As the maximum amps can not be supplied continuously, the diode starts tapering down on output from the start.

In contrast, a battery configuration with more volts, such as 2x RCR123, will yield a plateau/neutral shaped power curve. When 8.4V is used from the start, the voltage is so high at the beginning, that much less amperage is needed, and it is longer before you see the diode regress from too little amperage being available. The cells start far above the diode voltage, so amps are saved.

This was something more pronounced with LED flashlights, but now that we have diodes using 5 watts, it will happen and be seen here.

The problem with the second configuration using more voltage is that when the power drops, it drops hard and fast! If the cells are unprotected, they will need to be monitored carefully, because by the time the diode dims, the cells may already be damaged or ready to create a pipebomb in your hand!

Someone who wants a safe setup through continued use may choose a single larger cell (18650) and a boost driver.

Someone who wants maximum continuous output for a shorter time will use more of smaller cells, like 2x RCR123/18350 and a buck driver.

 

[brtaman]

Just checked the online catalogue of my local electronics shop - they stock the Lm317 for about $6. Now I saw a simple circuit diagram somewhere on the forum, let me go a hunting.

ON SEMICONDUCTOR|LM317BTG|V REG ADJ +1.2/37V, TO-220-3, | Farnell Australia

1.05$

Here ya go, I tend to buy from farnell quite a lot and I remembered they have an Australian division.

If they are anything like their UK equivalent expect instant shipping. Though it is not free...but hey you can alway stock up on other components. They have pretty much everything I need, rarely do I need to venture somewhere else...and I have an extremely varied shopping list usually.