Available online
Description
Illustrates several types and uses of servomechanisms, mentions possible problems with the home experiment and considers the amplifier design.
Illustrates several types and uses of servomechanisms, mentions possible problems with the home experiment and considers the amplifier design.
| Module code and title: | TS282, Electromagnetics and electronics |
|---|---|
| Item code: | TS282; 16 |
| First transmission date: | 30-09-1972 |
| Published: | 1972 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:23:48 |
| + Show more... | |
| Producer: | Tony Jolly |
| Contributors: | David Crecraft; John Sparkes |
| Publisher: | BBC Open University |
| Keyword(s): | Amplifier; Radar antenna; Robot devices; Rocket; Square wave signal; Thermal stability; Voltage fluctuations; Zoom lens |
| Footage description: | Programme opens with film clips showing servomechanisms in action: space rocket lift-off, antennas tracking it; plane flight deck, undercarriage being lowered and landing, a robot walking, mechanical hands. David Crecraft shows another example in the studio; the focussing mechanism of a TV camera. He then uses a special demonstration servo to show what happens when the gain and feedback conditions of the main amplifier are changed. The waveforms associated with underdamped, overdamped and critically damped motion are displayed. Using the home kit servomechanism, Crecraft demonstrates the effect of reversing polarity of connections to the input potentiometer and the motor, and of altering the gain. Rest of the programme is about the operational amplifier used for the servomechanism design study. John Sparkes discusses various points to note in the construction of the amplifier particularly thermal stability, using a block diagram and the circuit itself. He explains the features of the amplifier which deal with common mode and rail rejection of unwanted voltage fluctuations in the signal and power leads respectively. Finally he shows the effect of applying a square wave signal to the input and asks the viewer to consider why it produces a sawtooth output, as part of an SAQ for Unit 16. |
| Master spool number: | 6LT/70648 |
| Production number: | 00525_5006 |
| Videofinder number: | 710 |
| Available to public: | no |
