Fluke 5720A service manual Switch Matrix Operation 2.2V AC and 22V AC Ranges

5700A/5720A Series II Calibrator

Service Manual

2-90. Switch Matrix Operation: 2.2V AC and 22V AC Ranges

Refer to Figure 2-9 for the following discussion. AC 2.2V and 22V ranges are generated by the Oscillator assemblies and routed directly to the front panel binding posts through relays located on the Switch Matrix and Motherboard.

Line OSC OUT is connected to INT OUT HI through relays K19A, K18B, K27, and K30. INT OUT HI is connected to the OUTPUT HI binding post through relay K1 on the motherboard. Line OSC SENSE is connected to INT SENSE HI through relays K19B, K18A, K25, and K26. Motherboard relays K2 and K3 switch INT SENSE HI to the SENSE HI binding post during external sensing, or OUTPUT/SENSE HI during internal sensing.

Line OSC COM is connected to the OUTPUT LO binding post through relays K11 and K10 on the Switch Matrix. Switch Matrix relays K13 and K15 connect OSC SENSE LO to the SENSE LO binding post during external sensing, or OUTPUT/SENSE LO during internal sensing.

2-91. Switch Matrix Operation: 220V AC and DC Ranges

Refer to Figure 2-10 for the following discussion. In the dc 220V range, PA OUT HI from the Power Amplifier assembly (A16) is routed to the High Voltage Control assembly (A14), where it goes through relay K10 and becomes PA OUT DC. Line PA OUT DC is routed to the Switch Matrix and connected to INT OUT HI through relays K20, K19A, K18B, K27 and K30. Relay K1 on the motherboard connects INT OUT HI to the OUTPUT HI binding post.

Line PA SENSE DC is connected to INT SENSE HI through relays K20, K19B, K18A, K25, and K26. Motherboard relays K2 and K3 switch INT SENSE HI to the SENSE HI binding post during external sensing, or OUT/SENSE HI during internal sensing. PA COM and DAC LO are connected by relays K11 and K12, and connected to the OUTPUT LO binding post by relay K10. Switch Matrix relays K14 and K15 connect R COM to the SENSE LO binding post during external sensing, or OUTPUT/SENSE LO during internal sensing.

In the ac 220V range, Power Amplifier outputs PA OUT HI and PA SNS AC are routed to the High Voltage Control assembly (A14) where relays K10, K3, and K13 connect them to HV OUT and HV SNS respectively. HV OUT is connected to the OUTPUT HI binding post through relays K9 and K1 on the motherboard. Motherboard relays K10, K2, and K3 connect HV SNS to the SENSE HI binding post during external sensing, or to OUTPUT/SENSE HI during internal sensing. Connection to the OUTPUT LO and SENSE LO binding posts is done with relays on the Switch Matrix. PA COM is connected to the OUTPUT LO binding post through relays K11 and K10. Switch Matrix Relays K13 and K15 connected OSC SENSE LO to the SENSE LO binding post during external sensing, or OUTPUT/SENSE LO during internal sensing.

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