Sine Oscillator question.

[penelope]

Hi, I had questions about an oscillator circuit I wanted to make from this Linear application note. The circuit in question is on the last page of the pdf. I wasn't sure how to actually implement this circuit, are there switches between the normal mode and low distortion mode? And switches between the capacitors also? Also the potentiometer should they be separately adjustable or like a dual gang type?

 

[LvW]

Hi penelope,

I don`t know how deep your knowledge is regarding oscillators.
Nevertheless, the last page shows a classical WIEN oscillator topology - especially suited for 3 different frequencies.
Because the used amplitude stabilization principle (with filament lamps as PTC elements) requires to adapt the time constants there is a "low distortion mode".
I recommend, first to decide if you really need this specific oscillator with 3 fixed frequencies.
Otherwise, you should start from the basic WIEN topology.

 

[chuckey]

It is enough to wire either the low or high distortion mode - low distortion mode costs an extra two bulbs.
The capacitors are switched in pairs, so you need a 2 pole three way switch. The potentiometers should be be ganged together.
Frank