The use of the protective adapter, 2-pole is recommended for a number of electron tubes of the D series. The heating voltage should not be connected directly to the tubes, but with safety experiment leads to the adapter, which is electrically connected to the tubes.

 

The protective adapter serves as a protective circuit for the cathode heating against overvoltage, which prevents damage to the sensitive filament of the tube. The integrated relay switches off at heating voltages of approx. 10.5 V DC and approx. 8.5 V AC and switches on again automatically after reducing the heating voltage.

In school lessons or during practical training at universities it thus counteracts incorrect operation of the heating voltage control.

 

The protective adapter complies with the safety regulations for electrical measuring, control and laboratory equipment according to DIN EN 61010 part 1. 

 

Technical data:

Connections: 4 mm safety sockets

Switch-off voltage: DC: approx. 10.5 V; AC: approx. 8.5 V

Dimensions: approx. 75 mm x 45 mm Ø (matching the 2-pole connection cap of the tube)

Mass: approx. 70 g

 

compatibility:

The D Series tubes for which the protection adapter, 2-pole is provided are listed in the "recommended products" section of this page.