Heater Control Unit 200
The HCU200 unit is a control unit for a DC-load like a pitot/static tube heater to prevent aircrew from misleading information of non-working heaters or excessive current draw conditions for a variety of aircraft.
The HCU200 is consisting of:
- A solid state switch
- A current monitor with flag output
- Self test circuit
- Redundant switch drive circuit
The HCU200 contains one heater control circuit that includes a solid state power switch, a current sensing amplifier, a high- and low-current comparator and flag driver circuitry.
The warning flag signal provides a visual warning signal in case of operational errors of the heater circuitry which may be non-operational state, low-current-state or over-current condition. In case of any error-detection a +28VDC-flag signal is triggering a separate annunciator device installed in the A/C.
The high- and low-current limits are adjustable to match a specific application.