DC-DC Step Down, Need 11v.

[ElectroTactical]

Hello, I am new to electronics and am starting to create my first gadgets. Mintyboost, VU Meter, etc. The minty boost has 5v which got me started on an idea. My VideoCamera uses a 11v 1A power supply, I'm not sure how to change voltages from a chip. I have used search and couldn't find much so basically in short I am asking for assistance in learning. Idea's were to use a 12v SLA battery to power it, First I thought Just use an inverter and all but I'm assuming that would lose efficiency quite a bit by turning DC-AC-DC. What is your view?

Thank you everyone in advance for your help, I know dealing with people unfamiliar with the subject can be a pain but I am willing to read and learn if that helps.

-ElectroTactical

 

[transistor495]

You can use LM317 to get 5V,11V etc at 1A. Refer this thread:
https://www.electro-tech-online.com/threads/lm317-to-lm338-circuit-changes.28457/

 

[Ubergeek63]

You can use LM317 to get 5V,11V etc at 1A. Refer this thread:
https://www.electro-tech-online.com/threads/lm317-to-lm338-circuit-changes.28457/

Not for 11V from 12V!

 

[Hero999]

You need a low drop-out variable regulator.

 

[Leftyretro]

You could just wire two series diodes between your battery and your video camera. That would drop the battery from a nominal 12.6 to 11.4 which would work fine for your camera. Use 3 amp rated diodes.

Lefty

 

[Hayato]

You could just wire two series diodes between your battery and your video camera. That would drop the battery from a nominal 12.6 to 11.4 which would work fine for your camera. Use 3 amp rated diodes.

Lefty

Agreed! Simple and functional.

 

[SGC622]

You could just wire two series diodes between your battery and your video camera. That would drop the battery from a nominal 12.6 to 11.4 which would work fine for your camera. Use 3 amp rated diodes.

Lefty

that is the bias voltage that would be knocking the voltage down correct? the .5-.7 volts right?

 

[Leftyretro]

that is the bias voltage that would be knocking the voltage down correct? the .5-.7 volts right?

Yes, called the forward bias voltage and for standard silicon diodes it's around .6 but can vary a little with temp.

Lefty

 

[Ubergeek63]

Yes, called the forward bias voltage and for standard silicon diodes it's around .6 but can vary a little with temp.

Lefty

and current: a typical rectifier drops 0.6 or 0.7V at low current to 1.1V or more at rated current.

Dan

 

[chemelec]

Diodes will not be acceptable.

You need to consider that the battery will be Over 14 volts When Fully Charged. Than you will have 13 volts after your diodes.

A Low Dropout Regulator is the BEST Solution.

SEASONS GREETINGS.......Gary

 

[mvs sarma]

Diodes will not be acceptable.

You need to consider that the battery will be Over 14 volts When Fully Charged. Than you will have 13 volts after your diodes.

A Low Dropout Regulator is the BEST Solution.

SEASONS GREETINGS.......Gary

afterall the moment it is loaded it would fall back to 12V and I feel, 12V will be reasonably ok for 11V, as after few (less than single digit)minutes, at the defined load, the voltage would be less than 12.

It would be better to see the schematic of the application to confirm this thought.

 

[pfofit]

afterall the moment it is loaded it would fall back to 12V and I feel, 12V will be reasonably ok for 11V, as after few (less than single digit)minutes, at the defined load, the voltage would be less than 12.

Unless buddy tries to use the batt while it is still on the charger.

If anything can go wrong, it will. ....Murphy's law

 

[Thunderchild]

you can use a simple transistor zener diode circuit like this one. the zenner diode should be Vout + 0.7

 

[mvs sarma]

I suggest that ElectroTactical could measure the power supply adopter voltage while it is not connected to the camera and indicate us the exact voltage is 11.000V? or is it unregulated?

As the battery supposed to be used, changes from an initial value of 13.5 when fully charged to 10.5or so at discharged condition, perhaps you need to use a switching regulator with input 10.5 to 13V and output 11V and load 1.3 amps (keeping 30% margin).