Agilent Technologies L4400 manual Paired Drive With Combined Position Indicators

7Microwave Switch/Attenuator Driver

Paired Drive With Combined Position Indicators

The simplified schematic below illustrates the connection for a dual drive switch with an integral position indicator. The position indicators for this type of switch are electrically connected to the device’s drive coil. This is a typical arrangement for microwave attenuators. For these types of position indicators, you must make a parallel connection at the distribution board between the channel drive and the indicator input.

With these types of devices, positive voltage is present on the paired coil opposite the position the switch is currently in. Typically you will need to invert the logic level of the position indicator using the ROUTe:CHANnel:VERify:POLarity command.

As shown, Channel 01 was pulsed to close Port 1. The corresponding position indicator also closed.

The schematic shown is similar to the Agilent 876x series of switches and 849x series of step attenuators.

34945EXT	Y1155A	Switch
	Distribution
Logic Gate	Board
Sense	IND 11	Drive Port 2 –
Pull Down
Resistor
	+VR	Drive Common +
Logic Gate
Sense	IND 1
Pull Down	+VI
Resistor
Open Collector		Drive Port 1 –		Pivot
				Armature
Output Drivers	DRV 1
	DRV 11
		Port 1	Port C	Port 2
186			L4400 User’s Guide