This circuit is a must-have for all calculators. It's also probably the simplest circuit (used in calculator to count). Binary adder (as you can guess from its name) can sum two binary numbers.
You can have some problems when you will try to build and use an adder -
- There are two types of adders - half adder and full adder. Both can sum just two numbers (0,1), but full adder (unlike the half) can be connected to another full adder, which can operate with the 1st adder's output. That means you can sum more numbers when you have more full adders. Each new adder will add you one bit (read below)
- Adders (doesn't matter if half or full) are using binary code, so it can be confusing to work with them. Binary code uses just 0 and 1, so you can write a number in binary using just switches (ON=1, OFF=0).
- Binary code uses bits (you can image a bit as a place reserved for 0 or 1). Each connected full adder will add one more bit. The numbers you can sum are limited by the number of bits.
If you want to build up one for yourself, you can look at this scheme -
A stands for 1st addend input, B stands for 2nd addend input, Cin and Cout stand for connecting with previous/next full adder, S stands for output
Or you can download this world file and test it yourself - Binary Calculator world file
Tutorial for our worldEdit
The adder is on the left side and it's labeled, so it won't be problem to find it.
If you want to use it, don't forget these things -
- The adder has two lines of switches. The first line represents first addend and the second line represents second addend. Like this -
- Our adder has just 5 "showing" bits, so the max number you can get from it is 30 (15+15)
- It sums in real time, so please don't let the diodes interrupt you. You should look at them after finishing writing the addends.