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This sounds like it might have a proprietary part number stamped on it.
If you tell us the manufacturer of the circuit your 8-pin can is in, somebody might have
an idea. A lot of manufacturers print partial part numbers of their proprietary numbers,
and some of us have a little experience in the marking systems of SOME companies.
The ID you listed, doesn't narrow-down the possiblities for me.
Good luck. I spend almost half my time trying to ID proprietary part numbers.
If you tell us the manufacturer of the circuit your 8-pin can is in, somebody might have
an idea. A lot of manufacturers print partial part numbers of their proprietary numbers,
and some of us have a little experience in the marking systems of SOME companies.
The ID you listed, doesn't narrow-down the possiblities for me.
Good luck. I spend almost half my time trying to ID proprietary part numbers.
proprietary chip
The chip/can in question came from an Angle of Attack indicator made by Safe Flight Instrument Corp., of White Plains, NY. This is the computer for indicating the angle of attack (angle the plane is flying relative to the relative wind). The manufacture date was 1975 and the part number is 553-1. Safe Flight who is still in business will not release the schematics or parts lists I suppose for liability reasons nor will they repair the units.
Thank you for responding.
Dick
The chip/can in question came from an Angle of Attack indicator made by Safe Flight Instrument Corp., of White Plains, NY. This is the computer for indicating the angle of attack (angle the plane is flying relative to the relative wind). The manufacture date was 1975 and the part number is 553-1. Safe Flight who is still in business will not release the schematics or parts lists I suppose for liability reasons nor will they repair the units.
Thank you for responding.
Dick
how to spruce up a schematic
While trying to repair the Angle of Attack indicator/computer, I traced back all the components and trace lines into a schematic which was problematic s there are trace lines on both sides of the board and a lot were hidden by components. But the schematic is a mumble jumble of lines and components. Is there a rational way to redo this into a more enlightening way so it is easy to read? Is there a tutorial out there on this subject?
Dick
While trying to repair the Angle of Attack indicator/computer, I traced back all the components and trace lines into a schematic which was problematic s there are trace lines on both sides of the board and a lot were hidden by components. But the schematic is a mumble jumble of lines and components. Is there a rational way to redo this into a more enlightening way so it is easy to read? Is there a tutorial out there on this subject?
Dick
It's called reverse engineering. In this case you might take the components off and you see where the traces go. It is possible that the PCB has more than 2 layers, so you would need to investigate those as well as any interconnects between them.
Then you draw it out in a logical manner...
It's not trivial.
If this device goes in a real aircraft (as I suspect it does) then I am unfamiliar with the regulatory requirements concerning repairs and calibration of avionics and how these could affect you. It may be something to consider.
Then you draw it out in a logical manner...
It's not trivial.
If this device goes in a real aircraft (as I suspect it does) then I am unfamiliar with the regulatory requirements concerning repairs and calibration of avionics and how these could affect you. It may be something to consider.
reverse engineering
Steve, thanks for the reply. I will try and do as you say about removing the components. Without knowing what the National Semi can does, it will be hard to really figure out the circuits. What I do know is that a 7.7 ohm 3 watt wire wound resistor burned badly. This resistor is right at the input of the 28 volt power on the board and leads to a 15 volt device that acts like a zener diode, but has 3 legs. So I suspect something down the line is shorted and drawing too much current. The sensor in the wing (a varible capacitor depending on angle of attack) only has #28 wires, and they did not fry so I supect it is somewhere on the board. The device has a 5 amp circuit breaker that did not trip so I assume the resistor opened before it got to 5 amps which doesn't seem logical the way aircraft circuits are usually made.
Steve, thanks for the reply. I will try and do as you say about removing the components. Without knowing what the National Semi can does, it will be hard to really figure out the circuits. What I do know is that a 7.7 ohm 3 watt wire wound resistor burned badly. This resistor is right at the input of the 28 volt power on the board and leads to a 15 volt device that acts like a zener diode, but has 3 legs. So I suspect something down the line is shorted and drawing too much current. The sensor in the wing (a varible capacitor depending on angle of attack) only has #28 wires, and they did not fry so I supect it is somewhere on the board. The device has a 5 amp circuit breaker that did not trip so I assume the resistor opened before it got to 5 amps which doesn't seem logical the way aircraft circuits are usually made.
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