Pencil Resistor Circuit
More info below
I’d seen something about using a pencil to form circuit tracks some while ago. Rather than simply used as tracks, I found that with increased width, pressure or length the resistance value could be quite well controlled and tailored to whatever design was wished to be made.
Wondered if it would apply to a blocking oscillator. Take out the resistor, put in a pattern that would give a good range…working like a variable pot.
It works great and can bring highly individual designs 🙂
Just take the resistor out of any similar circuit and replace with your pencil track.
Pencil pressure has to be quite firm and the thickness of line will denote the resistance. Thicker the line, the less resistance.
The salts cell is made from 80% chili powder, 15% epsom salts, 5% magnesium fine shavings and water.
The water creates a reaction with the magnesium, that creates pressure in the cell if the top is put on the base (2 types of bottle tops). By quickly sealing the cell with hotglue or similar, the low pressure can be contained and is thought to help to form any crystals within.
Have fun !