What Is Oscillators?
Quite often we hear the word oscillators in the repair world. You heard other tech said “Is it oscillating”. You have heard of the horizontal and vertical oscillator IC in the Monitor. From datasheet you found an oscillator circuit inside the power IC like the PWM UC3842 and etc. So what exactly is the oscillator? An oscillator is an electronic circuit that converts dc to ac. That means the oscillator circuit or oscillator in the IC get the supply dc voltage and output an ac sinewave. They can be used to generate almost any waveshape ( sinusoidal and non sinusoidal) at almost any frequency.
If you compare the oscillator IC and the amplifier IC, you will know that amplifier IC are used to increase the strength (power) of a signal fed into it. This is different from Oscillator IC where this circuit is producing it owns signal (waveform)! That’s why when you look at the spec of the Power IC in SMPS, you would not see an input waveform pin but could only see the output pin and this output pin (pulse and high frequency) is the waveform produced by the internal oscillator circuitry to switch the Power Mosfet.