Agilent 34970A/34972A Data Acquisition / Switch Unit

Chapter 5 Theory of Operation
Switch Modules
34903A
Components in this discussion are located on the A1 circuit assembly
(34903-66501).
The control circuitry has two grouping of latches, relay drivers and
relays. The 20 channels are, for control purposes, arranged into 8 rows
by 10 columns.
The row latch, U102, and column latches, U103 and U104, control the
relays. The row drivers are divided into four groups of set and reset
drivers. Each group of row drivers controls five relays. The column
drivers operate as a pair. There are ten column drivers each controlling
two relays.
The 34903A provides 20 channels of Form C switching.
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