SECTION 14. INSTALLATION AND MAINTENANCE

Scientific offers the A21REL-12 Four Channel Relay Driver (12 V coil) and the A6REL-12 Six Channel Relay Driver with manual override (12 V coil) for use with the CR10.

In other applications it may be desirable to simply switch power to a device without going through a relay. Figure 14.10-2 illustrates a circuit for switching external power to a device without going through a relay. If the peripheral

to be powered draws in excess of 75 mA at room temperature (limit of the 2N2907A medium power transistor), the use of a relay (Figure 14.10-1) would be required.

Other control port activated circuits are possible for applications with greater current/voltage demands than shown in Figures 14.10-1 and 2. For more information contact Campbell Scientific's Marketing Department.

FIGURE 14.10-1. Relay Driver Circuit with RelayFIGURE 14.10-2. Power Switching without Relay

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