Campbell Scientific SDM-CD16S 16-Channel Solid State DC Relay Controller Module - Manual (Page 7)

SDM-CD16S 16 Channel Solid State DC Control Module
FIGURE 2. Equivalent Output Driver Circuit
3. Power Considerations
The SDM-CD16S power requirements may be large compared to most CSI
products. For most applications, an external power supply (see Figure 3) is
recommended to power the SDM-CD16S.
For some applications, it may be convenient to use the datalogger supply to
power the SDM-CD16S (see Figure 3). For long-term applications, the lead
acid power supply available with CSI dataloggers should be used, allowing the
batteries to be float charged. It is not recommended that the datalogger
alkaline supply be used to power the SDM-CD16S for long term applications.
If the datalogger lead acid supply is used, the current available from the wall
charger limits the SDM-continuous output current.
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