Hardware Reference
In-Depth Information
Figure 9.38
Motor driver circuits: (a) Darlington motor driver; (b) MOSFET
motor driver
Photo 9.11
Motorized linear actuator
with a conventional I/O device, this line can be tied high. A logic 0 present on a
particular data line will turn the corresponding Darlington output device 'off '
whilst a logic 1 will turn it 'on'. It should also be noted that the output stages are
protected against the effects of an inductive load by means of internal diodes.
These are commoned at pin-12 and this point should thus be returned to the
positive supply.
Driving mains connected loads
Control systems are often used in conjunction with mains connected loads.
Modern solid-state relays (SSRs) offer superior performance and reliability
when compared with conventional relays in such applications. SSRs are avail-
able in a variety of encapsulations (including DIL, SIL, flat-pack, and plug-in
octal) and may be rated for RMS currents between l and 40 A.
