Nowadays several circuits are used to understand blocking oscillators. The famous Joule Thief is the most popular to date for experimenters on different sites to understand the operation of a so-called blocking oscillator.
You can make a dimmable blocking oscillator with a very small 2N7000 type NMOS. Here is his circuit;
You have to enjoy building these basic circuits which lead to a greater understanding of oscillators. If you have other interesting circuits, don't hesitate to post them here.
The performance of the Thief joules is no longer to be redone with several serious studies demonstrating its usefulness like this one ;
Joule-Thief Circuit Performance for Electricity Energy Saving of Emergency Lamps (attached file)
Or this one;
The experiment proves that the system produces high gain pulse electricity and driven LED without broke it out. (attached file)
CONCLUSION
It has been proved that a Simple Blocking Oscillator produces high voltage pulses gain approximately to 7 times bigger than its input voltage. The gain is caused by the inductor’s magnetic field as a response of high speed pulse of current feeds from the power source that is regulated by the resistor and transistor, respectively.
Jagau