The function of an oscillator is to produce a sinusoidal wave shape of a specific frequency and amplitude. In doing so, the stability of an oscillator is very important. Depending on its application, an oscillator may be required to have either good frequency stability or amplitude stability; in many circumstances, both are required. In Series fed Tuned Collector Oscillator both the ac and dc components flow through the tank circuit. In Shunt fed Tuned Collector Oscillator the dc is blocked from the tank circuit and only the ac component flows in the tank circuit.
In this trainer the student measures the output frequency and amplitude by varying the capacitance of the tank circuit. This trainer has built in power supply, inductors, and active components to meet the above objective.
Hartley’s oscillator is intended for generation of high frequency signals like carrier wave signals in a communication system. This consists of a Tank circuit made up of an inductor and a fixed capacitor shunted by a voltage-variable capacitor network. Using this trainer the student experiments how variable frequency is generated. An external Oscilloscope of 15MHz is required for observation of the generated sine wave signals.
1. To connect a Hartley oscillator and observe and compare the collector and base Wave forms.
2. To check the frequency of the oscillator.
Colpitt’s Oscillator has fairly good frequency stability, can be used for wide frequency ranges and it is easy to tune. This is similar to Shunt-fed Hartely’s oscillator, except that two capacitors are used in the tank circuit instead of a tapped inductor. The frequency adjustment is possible both by varying the capacitor or inductor.
In this trainer a common-base Colpitt’s is used. There is no phase difference between the signal at the collector and the emitter signals. Therefore the phase of the feedback signal need not be changed. An external oscilloscope is required to view the generated signals.
Relaxation oscillator is a ramp generator. The ramp generator is often used as time base in sweep circuit in an Oscilloscope. The ramp generator has a good application in power electronics as control signal generation of thyristor pulse triggering circuits. Using this trainer the student can perform the measurements of various repetition rates of the oscillator. The device provides a pulse output at the B1 terminal for onward application of signal for pulse trigger circuits also.
This trainer has necessary power supplies, test points for observation of waveforms. An external oscilloscope is required to view the generated signals.
