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ArcticMyst Security by Avery
Using a DC/DC converter to power the laser
- Thread starter IgorT
- Start date
do you know what a Voltage divider is?viroy said:
its two resistors. i think you can make them fit
see http://en.wikipedia.org/wiki/Voltage_divider
you want to set
Vin to 7.5V-9V
Vout to 0.29V
and you want R1 and R2 to be in the order of Kohms
ah no i didnt know that, i was looking online and saw products. yea that will fit
i need help with the resistor values... what should i use?
sorry, im not in any kid of classes for electrical engineering so im struggling a bit to understand things for the first time.
any possibility i can get help with the schematic for the entire booster circuit including the lm3410 and divider? pretty please
i need help with the resistor values... what should i use?
sorry, im not in any kid of classes for electrical engineering so im struggling a bit to understand things for the first time.
any possibility i can get help with the schematic for the entire booster circuit including the lm3410 and divider? pretty please
IgorT
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Viroy... What do you need 7.5V for?
Not for a laser i hope? I almost get a feeling you want to put a linear driver (rkcstr's micro) after it?
The 3410 is not just a voltage booster. It boosts (or bucks) voltage to the exact level required for a certain current to flow through the load, and keeps adjusting it, so that the current is always the same. If you need it for a laser, the 3410 is a driver by itself. All it needs is a capacitor on the output, and you're ready to go.
Not for a laser i hope? I almost get a feeling you want to put a linear driver (rkcstr's micro) after it?
The 3410 is not just a voltage booster. It boosts (or bucks) voltage to the exact level required for a certain current to flow through the load, and keeps adjusting it, so that the current is always the same. If you need it for a laser, the 3410 is a driver by itself. All it needs is a capacitor on the output, and you're ready to go.
IgorT
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Well yeah, it is just a voltage booster, but it boosts the voltage in a way that keeps current constant, in the usual setup.
I was just trying to say, that since this is a laser forum, i almost have a feeling, he wants it for a laser..
More specifically, for a PHR diode with rkcstr's micro driver after the 3410..
That's why i asked, just to make sure there is no confusion.
I was just trying to say, that since this is a laser forum, i almost have a feeling, he wants it for a laser..
More specifically, for a PHR diode with rkcstr's micro driver after the 3410..
That's why i asked, just to make sure there is no confusion.
why would someone do such a thing?IgorT said:Well yeah, it is just a voltage booster, but it boosts the voltage in a way that keeps current constant, in the usual setup.
I was just trying to say, that since this is a laser forum, i almost have a feeling, he wants it for a laser..
More specifically, for a PHR diode with rkcstr's micro driver after the 3410..
That's why i asked, just to make sure there is no confusion.
wait, thats not the emoticon i want to use, try this one :-?
IgorT
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Well, there is more than one thread about "such a thing", and if you read the beginning of this one, i also first thought about "such a thing".. :-[
That's why i asked.... In case they think the 3410 can only boost the voltage to a certain value, and not regulate the current as well.
That's why i asked.... In case they think the 3410 can only boost the voltage to a certain value, and not regulate the current as well.
IgorT
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;D
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Hey I've got a weird problem with my lm3410 can anyone give me some advice?
I've got it set up and at least its boosting, so I suppose I've set it up right. But it doesn't seem to exactly be regulating. With a 1ohm resistor between FB and Gnd, I get about 100ma current, so about 100mv across those 2 pins. With a 2.2, that voltage goes to about 240mv, so the output is a bit above 100ma. Then with a 4.7, the FB goes to a whopping 380mv, and I get about 75ma at the output.
Any help would be appreciated.
I've got it set up and at least its boosting, so I suppose I've set it up right.
But it doesn't seem to exactly be regulating. With a 1ohm resistor between FB and Gnd, I get about 100ma current, so about 100mv across those 2 pins. With a 2.2, that voltage goes to about 240mv, so the output is a bit above 100ma. Then with a 4.7, the FB goes to a whopping 380mv, and I get about 75ma at the output. Any help would be appreciated.
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I was using 6 or 7 diodes as a test load before. With 20 ohms of resistance as a load it was a bit better. FB voltage was .16 so the voltage across the load was 3.25.
I still don't know what to put it down to. I've got a 4.7uh inductor, 2.2uf ceramic at the out and a 2.2 ceramic paralleled with a 10uf tant at the in.
Stupid hyperactive reference voltage :-[
I still don't know what to put it down to. I've got a 4.7uh inductor, 2.2uf ceramic at the out and a 2.2 ceramic paralleled with a 10uf tant at the in.
Stupid hyperactive reference voltage :-[
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Does the output cap provide the actual output (as opposed to filtering) on one part of the cycle? I'll try a tant (the biggest ceramics I have are 2.2)
It doesn't seem to be struggling since the FB voltage goes above 300mv when i use a 4.7 ohm resistor. Its just all over the place :'(
Could it be the inductor? I gave it a lot of heat when I was soldering since I figured it was a lump of metal.
EDIT: Just tried a tant. No difference, or not much.
It doesn't seem to be struggling since the FB voltage goes above 300mv when i use a 4.7 ohm resistor. Its just all over the place :'(
Could it be the inductor? I gave it a lot of heat when I was soldering since I figured it was a lump of metal.
EDIT: Just tried a tant. No difference, or not much.
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Could crappy board design account for this?
It can't make THAT much difference can it?
It can't make THAT much difference can it?
