Chapter 1: Functional Description
Infant Care Single Board Computer (ICSBC)
1-4 Service Manual
The motor driver circuit turns the DC motor coils in the incubator airflow fan motor on and off based on
feedback from the hall effect position sensors. This integrated circuit can also vary the speed and brake the
motor based on input signals from the Control Board.
The airflow sensor consists of an opto-coupler that outputs a clocking pulse proportional to the fan
movement. The signal is AC coupled to eliminate offset voltages and drifts. The resulting pulse is half wave
rectified and stored in a capacitor to yield a DC voltage proportional to the fan speed. If the fan stops or
there is no fan, this DC voltage becomes zero. The output signal is provide to the Control Board to indicate
proper airflow motor operation.
The canopy and elevating base motor control circuits consist of a series of three relays. The speed relay
connects the 15 volt secondaries of the toroidal transformer in parallel (with 15 volt output) for lowering the
canopy and in series (with 30 volt output) for raising the canopy and raising or lowering the elevating base.
The direction relay reverses the polarity of the voltage output from the speed relay depending on the
direction of travel. The E/H select relay switches the output voltage from the direction relay to the canopy or
elevating base motor depending on the switch that is pressed.
To minimize arcing in the relay contacts, the EH Activate MOSFET is switched off while the relays are
switched for the proper voltage, direction, and motor. Once the relays are set, the MOSFET is switched on
and proper voltage is applied to the correct motor.
The motor current sense circuit consists of a small signal transformer that produces a current proportional
to the motor current. The transformer output current is converted to a voltage and filtered. An output
voltage indicative of the motor current amplitude is provided to the Control Board. A subsequent
comparator then generates a digital level based on a specified current level. This results in a signal to the
Control Board indicating whether or not the e-base motor is stalled.
The Relay Board interfaces the user and system status input switch signals to the Control Board. Switch
signals include, e-base and canopy activation, canopy and heater door position, and humidifier reservoir
and water level status.
1.3 Infant Care Single Board Computer (ICSBC)
The primary function of the ICSBC is to provide a microprocessor based User Inetrface controller for the
infant care device. Other functions include serial communication interfaces to support both internal and
external peripherals and networks, display interface to support an internal LCD, and audio output to drive a
board-mounted speaker. The ICSBC is located in the display assembly.
Note: Speaker may not be installed.
The ICSBC is powered by the +12V DC power and the +5V DC power provided by the Rail Power Cable
(6600-0706-700).
The ICSBC has a 600MHz Intel Atom microprocessor with 512MB of DDR2 RAM and 4GB of Solid-State Drive
storage. The microprocessor has an integrated memory controller, GPIO, PCIe, HD Audio, real-time clock,
and video processor. The microprocessor communicates via PCIe to an Intel I/O Controller companion
chipset that provides the following additional interfaces: GPIO, UARTs, SATA, Ethernet, and USB 2.0.
The ICSBC provides the necessary circuitry to drive a 6/8 bit LVDS interface for an embedded LCD. It is
capable of driving either constant-voltage or constant-current power for LED backlights. It also provides
on/off and dimming control of the backlights. The ICSBC interfaces with the touch screen controller via an
internal USB 2.0 interface.
To Next Page
Loading...
Need help?
General
