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LM317 as a dc boost converter?

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Moha99

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The LM317 is a buck converter or a step-down regulator and is not suitable as a boost converter. I can't say for certain that someone has not found a way to use it as a booster, but that's not its usual function.

There are other ICs that can be used readily as a booster, but which one will be suitable for you depends on the load requirement.
 

Pjdd said:
The LM317 is a buck converter or a step-down regulator and is not suitable as a boost converter. I can't say for certain that someone has not found a way to use it as a booster, but that's not its usual function.

There are other ICs that can be used readily as a booster, but which one will be suitable for you depends on the load requirement.
Click to expand...

It's not stated weather its a step up or a step down.

LM317T/NOPB National Semiconductor | Voltage regulator,LM317T 37V | 533-8209 | Welcome to RS Online

I think its both since I have an input of 6 volts and it require 4.5 minimum to 40 volts maximum DC.
And an output 1.2 → 37V/DC and I can add an adjuster to regulate the required voltage.
 

@Moha99: The LM317 is a very well known, very popular device that has been around for a long time. It IS a step-down regulator. Believe me, I know, and so will most experienced members of the forum. I've used it in many of my designs and am very familiar with its specifications.

I said earlier that I can't say for certain that someone has not found a way to use it as a booster, but I said that only because sometimes someone comes up with a trick to use a device in an application for which it was not intended. An example is a CMOS logic gate used as an audio amplifier.

As I said before, you have to say what kind of load capacity you want to have with your converted DC output because that will determine which boost converter ICs and circuits are suitable.
 

Pjdd said:
@Moha99: The LM317 is a very well known, very popular device that has been around for a long time. It IS a step-down regulator. Believe me, I know, and so will most experienced members of the forum. I've used it in many of my designs and am very familiar with its specifications.

I said earlier that I can't say for certain that someone has not found a way to use it as a booster, but I said that only because sometimes someone comes up with a trick to use a device in an application for which it was not intended. An example is a CMOS logic gate used as an audio amplifier.

As I said before, you have to say what kind of load capacity you want to have with your converted DC output because that will determine which boost converter ICs and circuits are suitable.
Click to expand...



I'm not an expert in that field... I'm a beginner experimenting with a lot of things.

I just want to find a proper dc to dc converter that is perfect with my power source.

I have 6 volts/DC what regulator/converter/what ever... fits perfectly with my requirements?

Thank you I need 12 volts out and more +

---------- Post added at 12:28 ---------- Previous post was at 12:23 ----------

What is this dc to dc converter?

DC 3.5 volt step up converter.AVI - YouTube

I really want something similar to that.
 

You have to specify the maximum load current it should be able to drive, not just the voltage.
 

The video you referred, uses LM2577, a simple switcher, and uses a Ferrite Transformer to step up the output voltage. LM317 is an adjustable STEP DOWN voltage regulator. It will give you an output (input voltage-2 volts). Means if you feed it with 12 volts it will supply and adjusted voltage from 1.25 to 10 volts. This device has maximum 40 volts input.
You have 6 volts available but what is the current available ?. And after converting 6 volts to 12 volts what current you need to drive your load? You can use some DC/DC converter but again depends upon your available wattage and required wattage.
 

"Step-down", "step-up", "booster" are terms almost exclusively used in the context of switching regulators, that is: something that uses a coil for storing energy / converting the voltage.

LM317 is a simple linear regulator, which has in common with all linear regulators that Vout < Vin. That is, output voltage is always lower than input voltage. The voltage difference * current is wasted as heat (so with large Vin-Vout difference, efficiency is bad).

Another way for boosting DC voltages is a charge pump (requires a few capacitors), this is usually done for very light loads (mA range). Maxim has a number of IC's dedicated to this, but these are not suitable power conversion like wind turbine-related.
 

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