# creating a square wave with + - amplitude

Discussion in 'The Projects Forum' started by lostwithcircuits, Feb 6, 2012.

1. ### lostwithcircuits Thread Starter New Member

Feb 6, 2012
1
0
I need some help as I am a beginner with circuits. My end goal is to create a square wave with +-amplitude with pulse width of 5ms. I am using an arduino and command PWM to generate the two single sq waves (+5V to -0V) and (-5V to -0V) but I do not know how to combine the two outputs to create a single +-5V sq wave.
Thanks!

2. ### wayneh Expert

Sep 9, 2010
12,379
3,235
Are the two waves already related to each other through time, or is the comparison what you're looking for? If they're not related, you've really got a 3-state, 10V wave. You can have one at -5 and the other at +5 for ∆V=10, or they can be the same with ∆V=0, or the reverse of above, ∆V=-10.

More detail about what you want will get you a good answer here.

3. ### castley Member

Jul 17, 2011
31
0
A 741 Op Amp with + - 5V supply should give you the output you need. If one input is set at + 2.5 volts and you feed a 0 to +5 V SQ. wave in The output will be 0 when the input is + 2.5 V.

4. ### Ron H AAC Fanatic!

Apr 14, 2005
7,050
657
No it won't.
Lostwithcircuits, Are the three waveforms identical except for voltage levels? If not, we need a drawing of your two inputs and the desired output.