|Object Name:||SCADC Static Pressure Compensator (SPC)|
|Year of Manufacture:||Unknown|
|Location:||Main Object Store|
ACO 45127 Iss 1 DA1312
The Static Pressure Compensator (SPC) was used in the CPU-143/A (50-059-XX), one of the Standard Central Data Computer SCADC family units, and was used on the F-4 Phantom. Its function was to provide reversionary pneumatic Static Source Error Corrected (SSEC) data to the Pilot instrumentation. To do this, high pressure Engine Bleed Air was passed over a jet valve (inside the SPC) to create negative pressure; this is then regulated and mixed within the SPC under control of the SCADC electronics to create a pneumatic output equivalent to the Error Corrected Pitot-Static (Ps) pressure.
The tall structure with a stainless cylinder is the regulator diaphragm, the smaller diameter grey anodised structure with the pipe on top houses the jet valve and Solenoid Valve, whilst the black structure holds the Servo Valve which mixed the positive and negative pressures (under control of the Pc transducer) to create the SSEC output. (Akin to a hot/cold water mixer.)
The unit was designed by Andy Gibson in collaboration with Dunlop.