User manual

1 Introduction
Digital electronics is the basis of state-of-the-art computer technology.
"Digital" means that there are only clear on and off conditions in the
circuit, but no interim conditions like half on or three quarters on, as
known from analogue electronics. Therefore, there are fewer options on
first glance. If you use many digital lines at once, there is a great many
different conditions. Every single condition is referred to as a bit. An 8-
bit system can represent 256 conditions at once, a 16-bit system as
many as 65,636 (= 2 to the power of 16). If all conditions change
quickly, huge amounts of data can be processed and complex systems
like internet can be implemented.
The first attempts for the digital electronics should be performed with
the simplest components possible. A typical basic component is a so-
called gate, i.e. a circuit with inputs and one output. The condition at
the inputs determines what happens at the output. A typical example is
the NAND gate. The four-fold NAND gate 4011 used in the learning
package permits many circuit versions already. Several NAND dates
can be used to build circuits with other functions. Even an entire
computer is, in the end, built from such basic functions.
Gates can be used, e.g., to build flipflops or memory components that
maintain the last condition they have taken. A more complex flipflop is
the JK-flipflop, which internally is also built from gate functions. The
learning package contains a double JK flipflop 4027. The two ICs are
part of the CMOS-family 4000 and may be operated at operating
voltages between 3 V and 15 V. Therefore, they are great for simple
experiments and battery operation at 9 V.
This is an introduction of the components. The individual experiments
are performed on a pinboard. Every experiment has a circuit diagram
and a setup photograph included. The respective photograph is only a
suggestion; you may also place components differently. The connection
wires of the individual components were partially shortened for a better