Interesting Items
Interesting and historic items are shown on this page. Semiconductors To the right is a replica of the first transistor made at the Bell Labs, to the right is a Prototype Alpha processor from 1993 and a NatSemi 10cm silicon wafer from the 1970s behind.
Giessler Tubes: A typical ornate Geissler tube is shown here. This example also contains a fluorescing liquid, in a second jacket, around part of the discharge tube. The liquid glows due to the UV content in the light from the discharge. 'Mouse over' the two images to see them running. The tube is shown running with an AC HF supply.
Crookes railway Tube: Invented by Sir William Crookes, this evacuated tube has a paddle wheel which can move along the internal glass rails. The paddles are made from mica with fluorescent paint on the tips. A potential difference across the two electrodes can cause electrons to travel from the negative electrode (Cathode) to the positive electrode (Anode). Since the paddles turn, Crookes suggested that the cathode rays (electrons) must be particles with mass. It was later ascertained that it was not the direct action of electron bombardment that led to the movement, but the fact that the vacuum is not perfect. The remaining molecules of air act on the paddles either thermally or by their electrical charge.
Multitrack tape head: This is a large tape-head from a multi-track data recorder. There are 7 record/playback heads and it was one of two heads in a SE9000 recorder used to record radar data onto large tape reals. Data from a radar station feed was recorded onto a track (14 tracks available). The data was basically digital and this was converted by frequency modulation to be recorded to tape. The system was in service from around 1970 - 2000.
Wimshurst: Finally, this type of High voltage static generator was once used to power X-ray tubes and Geissler tubes before induction coils became more suitable. This is a reproduction version with some modifications to improve the performance. These are cleaver devices and use differentially charged petals on counter rotating disks to charge two Layden jar capacitors.
