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What is the advantage of flexdrives?

ginhev123

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Hello!

Something that I have not understood is, what is the advantage of flexdrives? Why would you use 2x flexdrives at 820mA each (for example) instead of just (for example) a Mohrenberg 1.62A driver for $10, instead of $70? What does the flexdrive have that Mohrenbergs driver doesn't have?

Thank you and I hope you can understand my question.
 

ARG

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Different types of drivers. The mohgasm driver is linear and the flex is boost.
 

ginhev123

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Different types of drivers. The mohgasm driver is linear and the flex is boost.
So if I have understood right, there are three types of drivers, buck, linear and boost? What are the differences between these?
 

Sigurthr

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A simple wikipedia run would have answered this....but since I'm bored I'll tell you.

A Boost Driver increases voltage. A Buck Driver decreases voltage. A Buck/Boost driver is a combination of both. A linear driver has a fixed voltage reduction across the regulator so it requires you to supply higher voltage than your load needs in order to get what your load needs to your load.

Want to run a 450nm diode which requires >4.5V off a single 3.7V lithium? you'll need a Boost Driver. Want to run a multiwatt IR diode which requires many amps at ~2V off a 12V low current supply? You'll need a Buck Driver. Want to build an inexpensive but wasteful driver when input power requirements are not an issue at all? Go for a linear.
 

ginhev123

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A simple wikipedia run would have answered this....but since I'm bored I'll tell you.

A Boost Driver increases voltage. A Buck Driver decreases voltage. A Buck/Boost driver is a combination of both. A linear driver has a fixed voltage reduction across the regulator so it requires you to supply higher voltage than your load needs in order to get what your load needs to your load.

Want to run a 450nm diode which requires >4.5V off a single 3.7V lithium? you'll need a Boost Driver. Want to run a multiwatt IR diode which requires many amps at ~2V off a 12V low current supply? You'll need a Buck Driver. Want to build an inexpensive but wasteful driver when input power requirements are not an issue at all? Go for a linear.
Ah.. Thank you for your answer. So basically, what it changes is basically the battery you would be using (if it's a handheld). Thanks.

+rep on both.
 
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DTR

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There are other differences. Linear drivers will pull less current but boost drivers will allow you to use single larger capacity batteries.

In the case of an 18650 host say if you use a linear driver set to 1.8A pulling 1.8A from the battery and an 800mAh 16340's that gives a run time of approximately 28 minutes between recharging.

But if you go with dual Flex'a set to 1.8A you draw on average 2.3A and used with a 2900mAh 18650 gives you aproximatly 1 hour and 15 minutes between recharging.

So that is 28 minutes vs 1 hour 15 minutes.


Also the flex is as the name says. Flexible. As it is also a buck driver so it will drive the diodes that have a lower forward voltage like the 635/650/IR diodes. Also in buck mode it turns the extra voltage into current instead of dropping it like a linear so if you have a 635 diode run by a Flex set to 800mA it will draw like 550mA. If you run that off the same 2900mAh 18650 you get 5 hours+ between charging.:eg:

There are also heat differences. With a 445 diode set to the higher currents they both produce a bit of heat but I think the linear drivers do produce a great deal more especially when they are running off fully charged batteries.

Now the great part is the linear driver is cheap and also pretty easy to build your own if you wanted with a few dollars in parts but the premade ones that Mo sells are great for ease of use. I have use them quite often myself.:beer:
 
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