Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Voltage / current draw

Tabish

0
Joined
Aug 30, 2009
Messages
689
Points
0
What voltage would a 140 be running at if the micro boost is set to 1A.

Need to know because I want to calculate the current draw at battery so I can estimate battery life.

EDIT:

So assuming the diode uses 4.4V @ 1A and the driver efficiency is 80%:

Its pulling 5.5W from the battery. Which means a current draw from battery of:

-1.31A when fully charged (4.2V)
-1.49A nominal voltage (3.7V)
-1.83A when discharged (3.0V)

The battery is a 14500 about 900mAh with a discharge rating of 1.5C.
This means a safe discharge of about 1.35A.

If I keep a short duty cycle, it should be able to get at least 30 min of run time right ?
 
Last edited:





Joined
Dec 29, 2009
Messages
3,136
Points
63
Calculate how much power your laser diode uses (power out) using its Vf at the current you desire and the current.
P=I*V


(Power in)*(driver inefficiency %) = power out
or
Power in = (power out)/(driver inefficiency %)

driver inefficiency you should use the lowest % stated on the datasheet of your driver.

Once you know how much power needs to be drawn from the battery, you can figure out, using P=I*V, what current will be drawn from the battery at a given voltage. As your volts drop, your current draw will increase.

Now go out and catch some fish :beer:
 
Joined
Jan 11, 2008
Messages
671
Points
0
I don't have my 445nm build up and running yet (waiting on some AixiZ modules), but here is some data from other people.

Lasersbee's data:
a140: 1050mA --- 4.34V
a140: 960mA ---- 4.31V
a130: 1090mA -- 4.79V

Exerd's data:
a1?0: 1000mA -- 4.5V
a1?0: 1000mA -- 4.6V

Hemlock_Mike's data:
a1?0: 1000 mA -- 4.25V

ff-racer's data
a1?0: 1000mA -- 4.24V

Hope this helps.
 
Last edited:

Tabish

0
Joined
Aug 30, 2009
Messages
689
Points
0
Calculate how much power your laser diode uses (power out) using its Vf at the current you desire and the current.
P=I*V


(Power in)*(driver inefficiency %) = power out
or
Power in = (power out)/(driver inefficiency %)

driver inefficiency you should use the lowest % stated on the datasheet of your driver.

Once you know how much power needs to be drawn from the battery, you can figure out, using P=I*V, what current will be drawn from the battery at a given voltage. As your volts drop, your current draw will increase.

Now go out and catch some fish :beer:

Yup I know that. What is the Vf for a 140 at 1A though ?

EDIT:

I don't have my 445nm build up and running yet (waiting on some AixiZ modules), but here is some data from other people.

Lasersbee's data:
a140: 1050mA --- 4.34V
a140: 960mA ---- 4.31V
a130: 1090mA -- 4.79V

Exerd's data:
a1?0: 1000mA -- 4.5V
a1?0: 1000mA -- 4.6V

Hemlock_Mike's data:
a1?0: 1000 mA -- 4.25V

ff-racer's data
a1?0: 1000mA -- 4.24V

Hope this helps.

Thanks. I'll just assume 4.4v then.
 




Top