Available online
Description
This programme is about the transducers mentioned in Unit 7 and TV4: their internal construction, the electrical output signals, and how these signals are coded and counted to provide positional in...formation. The programme is introduced by David Crecraft who shows the internal construction of an optical Moire' fringe encoder position transducer.
This programme is about the transducers mentioned in Unit 7 and TV4: their internal construction, the electrical output signals, and how these signals are coded and counted to provide positional in...formation. The programme is introduced by David Crecraft who shows the internal construction of an optical Moire' fringe encoder position transducer.
| Module code and title: | T291, Instrumentation |
|---|---|
| Item code: | T291; 05 |
| First transmission date: | 13-06-1974 |
| Published: | 1974 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:23:48 |
| + Show more... | |
| Producer: | Tony Jolly |
| Contributors: | J W Bruce; David Crecraft; Leonard Sayce |
| Publisher: | BBC Open University |
| Keyword(s): | Coded; National Engineering Laboratory; Optical transducer; Output waveforms; Signals; Synchro-resolver; Transducers |
| Footage description: | David Crecraft with an optical Moire fringe encoder position transducer. Some of the casing has been cut away to expose the inside. Crecraft explains how it works. Film shots from T291/04 shows Crecraft and J.W. Bruce examining the position transducers on a vertical drilling machine. Dr. Leonard Sayce, National Engineering Laboratory shows some typical gratings. He demonstrates the principles of optical interference transmission gratings in the context of position transducers. Sayce uses models of gratings, Moire fringes, to demonstrate his points. Crecraft with a radial grating optical transducer which has been wired to an oscilloscope. Phase shifted square waves are seen as the transducer is turned. Stan Hurst demonstrates natural binary and binary coded decimal counting using a large display board coupled to a control box containing the J-K logic circuitry. Crecraft demonstrates the counting process with a transducer coupled to a digital counter. As he turns the transducer shaft, numerical values are displayed on the counter. Crecraft with a model of a synchro-resolver. He points out its component parts, and explains how it works. Sinusoidal waves are generated and shown on an oscilloscope as Crecraft operates the model. Crecraft explains this in mathematical terms. Stan Hurst with a synchro-resolver. This transducer is wired to an encoder which in turn is coupled to a digital counter. Hurst turns the shaft and digital values are displayed. Crecraft with large scale models of coded disc transducers. He then shows a real coded disc transducer and goes back to the models to explain how they work. Crecraft discusses both the binary and the gray coded disc transducer. He explains the advantage of the gray coded transducer. Crecraft with an actual gray coded disc transducer coupled to a digital counter. He demonstrates. Crecraft sums up. |
| Master spool number: | 6HT/71104 |
| Production number: | 00525_5121 |
| Videofinder number: | 1065 |
| Available to public: | no |
