Available online
Description
The aim of the programme is to show the student how his home kit experiment on the simple single stage amplifier and the long tailed pair amplifier work.
The aim of the programme is to show the student how his home kit experiment on the simple single stage amplifier and the long tailed pair amplifier work.
| Module code and title: | TS282, Electromagnetics and electronics |
|---|---|
| Item code: | TS282; 11 |
| First transmission date: | 17-06-1972 |
| Published: | 1972 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:13 |
| + Show more... | |
| Producer: | Tony Jolly |
| Contributors: | Gary Alexander; David Crecraft |
| Publisher: | BBC Open University |
| Keyword(s): | Capstan; Differential amplifier; Drift; Linearity; Mechanical example; Model; Motor drive; Torque amplifier; Transistor amplifier |
| Footage description: | David Crecraft introduces the programme with a mechanical ecample of amplification. A rope is wound round a motorised capstan and the two ends pulled by four men and one girl respectively. The girl wins the tug-of-war with the help of the capstan. Crecraft then shows a model of a torque amplifier, and demonstrates on a real torque amplifier the problems of linearity and drift Gary Alexander discusses the simple single stage transistor amplifier used in the first home experiment. The DC operating conditions are measured and then an AC signal is applied to the input. The output waveforms at various points in the circuit are displayed. Phase reversal and clipping of the output signal are shown on the oscilloscope for different input signal conditions. David Crecraft discusses the long tailed pair differential amplifier used in the second home experiment. The amplifier is first DC balanced using the HEK multimeter and signals are then applied first to one input and then to both inputs simultaneously, and the output is monitored on the HEK oscilloscope, and on a larger twin beam scope. Gary Alexander illustrates instability in high gain amplifiers under certain feedback conditions, using the 741 operational amplifier first as a single stage amplifier and then with two stage amplification. Finally, he shows the presence of noise in the system on the oscilloscope, through loudspeakers and on a television screen. |
| Master spool number: | 6LT/70559 |
| Production number: | 00521_5001 |
| Videofinder number: | 705 |
| Available to public: | no |
