Abstract: A process is disclosed for driving an electrochromic element which consists of at least the following layers: a first electrode layer; a first layer in which ions can be reversibly intercalated; a transparent ion-conducting layer; a second layer in which ions can be reversibly intercalated; and a second electrode layer. One of the layers in which ions can be reversibly intercalated is an electrochromic layer and the other layer acts as a counter-electrode to the electrochromic layer. A voltage with values in a redox stability range of the electrochromic layer system is applied to the electrode layers and causes a change in color. The process is characterised in that the current (I) which flows through the electrochromic element is continuously measured. During a starting phase of the change in color, the voltage (U) rises or diminishes continuously to a maximum, predetermined, temperature-dependent end value (Umax).

Abstract: A window antenna for a motor vehicle body opening in which the antenna is used for mobile radio in a double-band operation with bands have a long wavelength L and a short wavelength K. Two monopoles L/4 and K/4 are electrically connected by a foot portion to which the core of the coaxial feeder cable is adjoined. Two radials corresponding in dimensions to the monopoles can extend along at least one edge of the pane and parallel to the frame member. The radials are connected to the shielding. The spacing of the radials from the frame, the width of the radials and their lengths are selected so that the radiation characteristics are optimized and standing surface waves on the shielding of the cable is avoided.

Abstract: An anti-eavesdropping window structure in which the inner and outer panes, separated by a spacer frame have thickness d and D such that D/d is at least equal to 1.5. The space between the panes is filled with a gas mixture having a density in excess of that of air and a body-sound generator applied directly to the outer pane generates thermal noise over a frequency range of 200 to 3000 Hz to superimpose a level of such noise of at least 20 dB on transmitted sound.