Grossel
Well-Known Member
Hi. I know that is several aproach how to make an analog adder. Exept from the regular one (inverter with more than one input resistor) I found out another way to achieve the same:
**broken link removed**
It might working fine, but there is one issue I'll try to solve: Is there possible to make an non-inverting adder this way, without adding an extra inverter block? I hope that can be done in a similar way.
Reason I want to do it this way is to try avoiding need for negative voltage supply. A regular adder requires negative voltage supply because of the following inverter stage.
I tried to think of a way to overcome this and ended up with this:
**broken link removed**
But I have serious doubt that this will ever work. One reason is that input voltage have to be much higher - near power supply. And of course the output voltage can only be less than those two input voltages, unless i add an non-inverting stage.
My brain goes in saturation - Is there anybody that can think out a circuit that is somewhere between those.
Final goal is having an adder that consist of no more than two opamps (next stage have high impedance input = no need for voltage follower) but use small voltage through a pair of low-value resistor to control current so I get an output that is inputs added together.
**broken link removed**
It might working fine, but there is one issue I'll try to solve: Is there possible to make an non-inverting adder this way, without adding an extra inverter block? I hope that can be done in a similar way.
Reason I want to do it this way is to try avoiding need for negative voltage supply. A regular adder requires negative voltage supply because of the following inverter stage.
I tried to think of a way to overcome this and ended up with this:
**broken link removed**
But I have serious doubt that this will ever work. One reason is that input voltage have to be much higher - near power supply. And of course the output voltage can only be less than those two input voltages, unless i add an non-inverting stage.
My brain goes in saturation - Is there anybody that can think out a circuit that is somewhere between those.
Final goal is having an adder that consist of no more than two opamps (next stage have high impedance input = no need for voltage follower) but use small voltage through a pair of low-value resistor to control current so I get an output that is inputs added together.