Abstract: Time domain radar signals are transmitted and received from vee dipole antennas on circuit boards. The antennas are formed by spaced deposited copper pads and discrete surface mount resistors soldered between the copper pads. The antenna feed-points are connected directly to adjacent transmitting and receiving circuits on the same printed circuit board. Traces are printed on a middle layer of a strip of printed circuit board. Vias connect ground planes on opposite sides. Artifacts are reduced, and signal properties are controlled.

Abstract: A spare battery holder is provided having a clip of a spring-construction material adapted to engage over the exterior of the electronic device. A battery holder, attached to the clip is provided with upper and lower lateral extensions having gripping means thereon in facing relationship. One of the lateral extensions is provided with a small diameter hole adapted to receive the positive electrical anode contact of the battery while the opposite lateral extension is provided with a spring adapted to bear against the flat negative electrical cathode. The spare battery is then compressed between the two lateral extensions.

Abstract: A door knob and lock assembly having a pair of knobs, a latching bolt operable by the rotation of the knobs, and a turn button to selectively arrest the movement of the bolt to place the assembly in locked condition. A battery operated electrical circuit including a switch operable by the turn button, and a light emitting diode mounted within the door knobs so as to be operable on locking the door to provide a flashing light visible from the outside of the door.