# Best solution for square wave generator

Discussion in 'Microcontrollers, Programming and IoT' started by mikus, Jan 4, 2015.

1. ### mikus

3
0
Jan 4, 2015
Hello

I need to build signal generator for square wave were i can change amplitude from 0v to 12v (60Hz).
It is necessary for LCD display shutter testing, LCD display have capacitor characteristics

and I need to drive it and measure

maximum (peak) current mA ,
minimum current (leakage or plateau current) μA,
RMS average current over multiple reference drive cycles μA
RMS average power (RMS average of I(t) V(t) product) over multiple reference drive cycles (μW range)

I hope for help, and thank you for attention

2. ### Gryd3

4,098
875
Jun 25, 2014
Give us some more detail.
How precise do you need to 'square' wave to be?
Is there going to be a duty cycle?

Does the frequency you chose need to be exactly 60Hz? Use in Television equipment or power-grid related equipment of any kind usually runs a little slower... like 59.94Hz

Simplest solution I can think of, is getting or building an adjustable voltage DC power supply in which you can connect a low value shunt resistor that you can use to calculate current draw.
Once you have this, you can make a simple timer with a 555 that will drive a transistor or mosfet that will control the output of the power supply.

mikus likes this.
3. ### mikus

3
0
Jan 4, 2015
Hello

I have need for microcontroller controlled bipolar square wave generator +-15v with adjustable voltage.

I am dreaming of a signal generator witch one i can turn on with arduino, but wen i turn it off i have +15 DC voltage

Frequency must be 60hz but voltage would be nice to have adjustable, 5v,7v,12V,15V

I have bipolar supply +- 15v

I will grateful for any help or ideas

(Moderator action: New post moved to this thread -- KrisBlueNZ)

Last edited by a moderator: Feb 26, 2015
4. ### KrisBlueNZSadly passed away in 2015

8,393
1,271
Nov 28, 2011
There are a thousand answers to this question. It all depends on what you're trying to achieve. Start by telling us about the whole project, then we will be able to recommend a suitable way to do what you want to do.

5. ### mikus

3
0
Jan 4, 2015
My project is a peak and leakage current tester for LCD Shutter cell
LCD cell must be connected to 60Hz bipolar voltage +-1% is Ok
Then with shunt resistor I measure current on LCD cell.
I now how to get peak current value, but I have problems with leakage current.
I think I could turn on frequency generator with arduino and measure peak current, then turn off generator and measure leakage current, like 100ms measuring peak, 100ms measuring leak current