Step Up Battery Voltage Problem

[tasha]

Good Day Sirs

I would like to ask for consultation to everyone who will be able to help me with my problem

i made an adjustable stepup voltage dc to dc converter, i was able reach my desired voltage but the problem is, i think it does not supply enough power, so even if i setup the voltage to 6volts once i plug in the device to the circuit the 6volts output drops to like 3+volts? can anyone help me with this? by the way here is the attached pic of the diagram i made using the lm2577

 

[tasha]

do i have to replace my regulator or can it be solved?

 

[audioguru2]

You forgot to tell us how much is your output current.
You also did not tell us how low the battery voltage drops with your load.

 

[tasha]

huhuhuu...

sorry sir don't have a tester for current output=(

i set it to 6 volts then when loaded it dropped to 3.83v=(

 

[tasha]

by the way thanx sir for the interest to help=)

 

[audioguru2]

Every cheap multimeter can measure DC current. Buy one. It can also measure the battery that might have its voltage drop when the stepup IC has a load.

 

[ARUN CHOWDARY]

dont u tried by changing the load resistance

 

[tasha]

ok sir was able to test it loaded at 1.6amps sir

 

[audioguru2]

was able to test it loaded at 1.6amps

But its max allowed load is 800mA so you overloaded it. Reduce the load current to 800mA then it should work well.

 

[tasha]

is there by any chance that the circuit be tweaked so it can handle load that big?

or maybe i have to replace the stepup regulator?

 

[audioguru2]

is there by any chance that the circuit be tweaked so it can handle load that big?

No. Your output current is much too high and your input voltage is too low.

maybe i have to replace the stepup regulator?

Select a more powerful stepup regulator that works with your low input voltage.

 

[tasha]

sir audioguru, thank you very much for the patience in answering all of my questions, truly you are a wonderful asset her in electronicslab community=) muah muah=O



will this regulator do?

MAX1709 Description
4A, Low-Noise, High-Frequency, Step-Up DC-DC Converter

 

[audioguru2]

Didn't you look at the datasheet of the MAX1709?
Its max output voltage is only 5V, not 12V.

 

[tasha]

@sir audio

it's ok, what i need is voltage that can be adjusted from 3.7v to 5.5v only, don't really need up to 12volts sir=)

so can the new regulator do the trick for my requirements sir?

 

[Hero999]

If you look at the Linear Technology, National and Maxim Semiconductor websites (Google them, if you don't know) you'll find a wizard to help you find the correct part. There's also a program which will help you to design the circuit.

 

[tasha]

thanx sir hero, will do that now=) thanx=)