Looking for Latest Electronics Project Kits? Hartley oscillator was invented in 1915 by the american engineer Ralph Hartley while he was working for the Western Electric company. The original design was tube based and he got a patent for it in the year 1920. In a Hartley oscillator the oscillateur hartley pdf frequency is determined by a tank circuit comprising of two inductors and one capacitor.
The inductors are connected in series and the capacitor is connected across them in parallel. In the circuit diagram resistors R1 and R2 give a potential divider bias for the transistor Q1. Re is the emitter resistor, whose job is to provide thermal stability for the transistor. Ce is the emitter by pass capacitors, which by-passes the amplified AC signals.