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Starting electronics
Other bistables
There is more than one type of bistable — the SR-type is in
reality only the simplest. They all derive from the SR-type
bistable however, and so it’s the SR-type bistable that we’ll
use as the basic building block when making them.
The clocked SR-type bistable
Figure 11.8 shows the clocked SR-type bistable. It is a simple
adaptation of the basic SR-type NAND bistable, in that it features
an extra pair of NAND gates, which not only allows inputs
which do not require inverting, but also allows a clocked input
to be part of the circuit’s controlling mechanism.
Now, a clock circuit can be made from something like a 555
astable multivibrator (as we saw in Chapter 5), and how it is
made is unimportant to us here. What is important, on the
other hand, is that a clock means that several bistables can
be synchronised, all in time with the clock.
Figure 11.8
A clocked SR-type NAND bistable
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