Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic 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

How to increase voltage

Status
Not open for further replies.

binary2007

Newbie level 3
Joined
Sep 30, 2007
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,309
how to increase voltage

Hi! I'm new to electronic design and I can't find out well. I have one simple task. Microcontroller produces PWM (10Hz-1000Hz) duty cycle can vary from 10% to 90%. This is not a problem because I am more programmer than electronic engineer. But that signal should be amplified in some way so I can get from 5V-45V voltage and current not more than 100mA. Is there any similar scheme that I can implement. Should I use transformer or it can be done without it.
Thanks in advance.
 

hassenman

Advanced Member level 4
Joined
Nov 29, 2004
Messages
117
Helped
4
Reputation
8
Reaction score
1
Trophy points
1,298
Activity points
912
increase voltage

Hi binary2007,

Well, if you want to get up to 45 V from your 5 volts PWM source, you can always use an OP AMP and fix its gain to 9, ( u can manage to put a little pot in the feedback loop of the AMP for fine adjesting later on ). concerning the current a simple transistor will do the job. I recommend using a feedback of your output wich you will connect to your controller if this latter have any A/D converter, such a feedback will allow you to exactly match the request output voltage.
If this is what you're looking for i can draw a little schematic of the Idea.

Hope this Helps,

Hassen.
 

    binary2007

    points: 2
    Helpful Answer Positive Rating

leo_o2

Advanced Member level 4
Joined
Sep 3, 2004
Messages
1,324
Helped
277
Reputation
556
Reaction score
241
Trophy points
1,343
Location
China
Activity points
5,761
increase voltage circuit

You can use a level shifter IC.
 

binary2007

Newbie level 3
Joined
Sep 30, 2007
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,309
how to increase voltage output

Hi hassenman!

I would appreciate you draw me that scheme. Thank You. I think that might solve my problem.
 

Old Nick

Advanced Member level 1
Joined
Sep 14, 2007
Messages
480
Helped
68
Reputation
136
Reaction score
18
Trophy points
1,298
Activity points
4,243
voltage increase

I wouldn't use an op-amp for this, you have slew rates etc to worry about.

Look for an Open-Collector Buffer which will support an output of 45V, the data sheet will give you the the info you need to know to configure it. The chip will only require an external resistor.
 

raka200

Member level 2
Joined
Aug 2, 2007
Messages
48
Helped
2
Reputation
4
Reaction score
0
Trophy points
1,286
Activity points
1,625
how do you increase voltage

Hi !!!

If you want to learn a little bit of analogic electronic, you could use transistors, and some resistors.
You could easily find a transistors which accept voltage of 45V and 100mA of current.

If your load doesn't need to be referenced to GND, you could use only one NPN transistor. But if your load need to be connected to GND, you shoud use 2 transostor : one PNP as a switch between your load and the 45V, and one NPN to produce the correct voltage command for the PNP.
I could send you the schematic if you want.
Bye !!!
 

hassenman

Advanced Member level 4
Joined
Nov 29, 2004
Messages
117
Helped
4
Reputation
8
Reaction score
1
Trophy points
1,298
Activity points
912
how to increase volt

Hi binary2007,

i'm sorry for the delay, i included here a part of a circuit i used lately.

i'm assuming here that u already got your 0 -- 5 volts pwm working and you already filtered it.

You will use the filtered PWM signal and amplify it with this AMP op based circuit. First thing to carry about is the use of a high voltage AMP OP ( 45 volts at least ).
I think Slew rate won't be a problem to your design since you're dealing with already stabilized voltage, slew rate would be benificial to your signal if it's still fluctuating .
The use of the Q1 transistor will allow u to reach the sighted amount of current, while Q2 with Re1 will prevent short circuits.
Of course, u'll have to choose the proper values to your components, making sure AMP op Gain is 9 ( the pots in the feedback loop will allow u to ajust that gain exactly to the requested value ...).
Now when everything is working ok , you will have to measure the output of your design through an A/D converter ( assuming that your controller already got one ).
with that u'll be able through your software to exactly match any requested voltage by adjusting duty cycle of your PWM signal . . .

This is the way i see it :) . . .

Hope this helps,
Hassen.
 

2339

Junior Member level 2
Joined
Oct 5, 2007
Messages
21
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Palestine
Activity points
1,378
voltage increaser

This is the solution
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top