Emerson Process Management ControlWave EFM 3808 User Manual
Page 36
1-20 / Introduction
CI-ControlWave EFM
Figure 1-11 - Digital To Relay I/O Board
1.3.12 21V Power Supply Option
The 21V Power Supply is a continuous mode boost switching type power supply. It is based
upon a low power, low noise circuit that produces 21 Volts from a 12V input. Power
shutdown is not an option with this unit since it employs a Boost circuit; therefore, the 21V
Power Supply must be powered continuously.
Figure 1-12 - 21V Power Supply Board
The 21V Power Supply is mainly used in conjunction with Temperature and Pressure
Transmitters which require a higher than +12V but lower than 21.4V (
± .8V) input supply
to operate.
1.3.13 Power System
Power may be provided by a rechargeable 12V, 33AH Lead Acid Battery used in conjunction
with either a 30 Watt or 40 Watt Solar Panel or power may be externally supplied.