ENGINEERING LOGIC DIAGRAMS
Figure 9 Type-Three Time Delay Device
Upon reciept of an input signal, Type-Three Time Delay Devices provide an output
signal for a specified period of time, regardless of the duration of the input. Figure 9
demonstrates the signal response and illustrates the symbol used to denote the timer.
Complex Logic Devices
In addition to the seven basic logic gates, there are several complex logic devices that may be
encountered in the use of logic prints.
Memory devices - In many circuits, a device that can "remember" the last command or
the last position is required for a circuit to function. Like the AND and OR gates,
memory devices have been designed to work with on/off signals. The two input signals
to a memory device are called set and reset. Figure 10 shows the common symbols
used for memory devices.