Fluke 5720A service manual 3511 A16 Incorrect PA Input, Spare, 3520 A16 PA Oven Regulation Fault

Models: 5720A

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3511 A16: Incorrect PA Input

5700A/5720A Series II Calibrator

Service Manual

resulting in a -130V Power Amplifier output. The second is the normal 220V dc operation with the input voltage from the DAC assembly. In this mode the Power Amplifier is outputting 22.1V, 100V, 219V, and -219V. In each mode the Power Amplifier output voltage is measured to be the nominal ±10% by connecting MUX3 to the SDL line where it is measured by the adc circuit on the DAC assembly. A failure indicates the Power Amplifier assembly (A16) is probably at fault.

3511 A16: Incorrect PA Input

The instrument is set to the dc 220V range with two modes of operation. The first is with the Power Amplifier input voltage being the 6.5V reference voltage (BRF6, BSRF6) resulting in a -130V Power Amplifier output. The second is the normal 220V dc operation with the input voltage from the DAC assembly. In this mode the Power Amplifier is outputting 22.1V, 100V, 219V, and -219V. The 6.5V reference input or the resulting -1.105V, -5.0V, -10.95V, and 10.95V respectively from the DAC, is measured to be the nominal ±10% by connecting MUX5 to the SDL line where it is measured by the adc circuit on the DAC assembly. A failure indicates the Power Amplifier assembly (A16) is probably at fault.

3512 Spare

This fault code is not used.

3513 Spare

This fault code is not used.

3514 Spare

This fault code is not used.

3515 Spare

This fault code is not used.

3516 Spare

This fault code is not used.

3517 Spare

This fault code is not used.

3518 Spare

This fault code is not used.

3519 Spare

This fault code is not used.

3520 A16: PA Oven Regulation Fault

The heater voltage of the Power Amp hybrid is measured by connecting MUX7 to the SDL line where it is measured by the adc circuit on the DAC assembly to ensure the

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Page 320
Image 320
Fluke 5720A service manual 3511 A16 Incorrect PA Input, Spare, 3520 A16 PA Oven Regulation Fault