# Divide two different AC voltage

#### MrChips

Joined Oct 2, 2009
19,724
What are the frequencies of the two AC signals?

#### Romie77

Joined Jan 4, 2020
12
What are the frequencies of the two AC signals?
50HZ. Is it important if we do work on this IC?

#### MrChips

Joined Oct 2, 2009
19,724
50HZ. Is it important if we do work on this IC?
Just checking.
What happens when the denominator crosses zero?

#### RPLaJeunesse

Joined Jul 29, 2018
76
How fast do you need the result? Is it safe to assume always a sine wave? Might be better to gain up the signals a small bit (say to ~3V p-p) and use a simple micro to capture the signals via ADC, filter out the DC biases, determine the average AC values, and divide the results to get the ratio. An on-chip PWM or simple I2C DAC could make the result a DC voltage. (I'd try it with a "Bluepill" since the ADC will be faster than an those on an 8-bit Arduino, so better for "almost simultaneous" sampling.)

#### Romie77

Joined Jan 4, 2020
12
Both values varies from 0.1 to 3V AC.
AD532 is the only available IC, so I need to work on it.
I thought to simulate the result. But this IC is not present on 'multisim' (online) software.
Is there any free simultor available online?

#### crutschow

Joined Mar 14, 2008
23,722
What exactly is the output result you expect from this division?
Note that dividing by zero, when the sinewave goes through zero, is undefined and will likely saturate the chip.

I couldn't find an AD532 Spice model, but I do have an AD633 model, which is a similar device, for the free LTspice simulator program from Analog Devices/Linear Technology, which I use.

#### Romie77

Joined Jan 4, 2020
12
I think the way in which I had described the issue is not perfect. Sorry. Actually, I dont need to divide actual sine wave but I need to divide two AC values read by multimeter.

#### crutschow

Joined Mar 14, 2008
23,722
I think the way in which I had described the issue is not perfect. Sorry. Actually, I dont need to divide actual sine wave but I need to divide two AC values read by multimeter.
So how would you do that, other than with a calculator?

#### Romie77

Joined Jan 4, 2020
12
So how would you do that, other than with a calculator?
Exactly!! I was looking for a circuit to get output reading directly and bypass calculator uses.
I got the datasheet of AD532 which shows divider circuit. But I am unable to simulate it as I had discussed in post#6.

#### MrChips

Joined Oct 2, 2009
19,724
In that case, take the two AC signals, rectify and smooth to DC and then do the division.