Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Increasing Current on my voltage regulator

Status
Not open for further replies.
O

ObedMiramontes1

Newbie level 4
Newbie level 4
Joined
Oct 22, 2010
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,330
I designed a voltage regulator with that regulates 19 volts and outputs 13.5volts.
I did this by using a 5.1 Zener diode and TL081 op-amp and a npn BJT... I connected the zener diode to the op-amp and by calculating the resistor values adjusted the gain of the op-amp to get my output of 13.5. The thing is that i need more current out of the regulator... so far, i only got a few milliamps and i need at least 1.5A...

Any ideas?

This voltage regulator is going to be connected to a charge regulator to charge a 12 Volt 20Ah battery!
 

Check the data sheet for the PB137 device from ST. It will do the whole job, handling the current and it has overload protection, all in one 3-pin component.

Other than that, you need to further amplify the output current with a second transistor. Without seeing your schematic it's difficult to show the best way of doing it.

Brian.
 
For those who are helping me, this is the schematic i have put together so far!

Thanks!

---------- Post added at 18:57 ---------- Previous post was at 18:56 ----------

 

I’d suggest some initial changes .. see attached drawing ..
Make sure that Q8 is a power transistor, and that V3 is a voltage source of 19Vdc ..
To fine-tune the output voltage you may add a variable resistor in series with R2 ..

Also, you will need to add some caps here and there, for example on the output and the 19V-rail, to make sure that the circuit is stable ..

IanP
:wink:
 

Attachments

  • Obed2.JPG
    Obed2.JPG
    38.5 KB · Views: 169
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top