Analog division / One quadrant multiplier

[juz_ad]

I'm researching Division circuits to divide an input voltage of between approx. 0.1 to 10V by a reference voltage of approx. 0.8V. The planned circuit is part of an RMS to dBu converter.

There's a standard 4x op amp 4x transistor circuit in some of the major app notes and Walter Jungs op amp book but I've also been reading about quadrant multipliers.

Firstly - is it possible that division can be performed with a one quadrant multiplier?

Secondly - can anyone point me to some schematics for a one quadrant multiplier? Most of my books jump straight to four-quadrant,

I'm looking for transistor/op-amp circuits - not dedicated ICs please.

Thanks.

 

[crutschow]

Why no ICs? Is this homework?

 

[juz_ad]

Why no ICs? Is this homework?

It's not homework.

I don't want to use ICs simply because I'd like to build it myself. I'm semi-familiar with some of the elements of the op-amp multiplier/divider circuits as I've done anti-log conversion before and this seems like not too far a jump from that.

I asked about quadrant multipliers because they appear to be based on current mirrors and I've done a little bit of work with transistor OTAs. A four quadrant multiplier is more complex than I want or need (I think…) - but I figured, if I could do division with a one-quadrant multiplier - then that might be a simpler circuit to get me started.

I can always build a more complex one later - or give up and use a dedicated IC!

Thanks.

 

[crutschow]

Perhaps a voltage-controlled amplifier would do what you want.

 

[pferenc]

Hi Juz_ad!

In the past, I was looking for a solution to an analog divider with single power supply, but only managed a multiplier circuit based on the MC1495. With the divider circuit I have not such success. I think that may be a base of your analog divider development.

Feri.

Sorry for my English.
If you need the complete PSpice file I will post it.