http://cappels.org/dproj/simplest_LED_flasher/Simplest_LED_Flasher_Circuit.html

Curious, I thought the Transistor only conducts if the base voltage is > collector voltage?..... how come this circuit works?

 

In the case of an NPN transistor, the base needs to be about .7 volts more positive than the emitter.

 

Look at the datasheet of any silicon transistor. The absolute max allowed emitter-base voltage (reverse voltage) is only 5V to 7V. Because any higher and the junction conducts with "avalanche breakdown".

This oscillator circuit has the emitter-base junction conducting with avalanche breakdown and it is in series with the forward-biased base-collector junction. That is why it uses a 12V supply.

 

I can't view the circuit link in the first post, but it sounds like a thyristor or an SCR would be safer than forcing a bipolar transistor to conduct. My 2¢
http://www.allaboutcircuits.com/vol_3/chpt_7/5.html

 

http://cappels.org/dproj/simplest_LED_flasher/Simplest_LED_Flasher_Circuit.html

Curious, I thought the Transistor only conducts if the base voltage is > collector voltage?..... how come this circuit works?

This is an interesting circuit.