Wiring & diagram Info

Like many of us, Nyle Steiner has long aspired to building a homemade transistor. While considering possible way to achieve this, he stumbled upon the interesting idea of building a FET transistor from a cadmium sulfide photocell.

Normally used to detect light, the photocell is pretty close to what one would need to make a transistor. The device consists of two pieces of metal that are separated by a very thin layer of a cadmium sulfide semiconductor. The semiconductor is normally an insulator, which means that no electricity can flow from one of the metal legs to the other. However, when light (photons) hit the surface of the semiconductor, they knock electrons free, and allow some current to flow across the semiconductor. To make a transistor, though, the device needs to react to electricity, not light. Nyle realized that the photocell could be used as a transistor if an insulated gate was added to the top of it. A bit of scotch tape and water later, and he claims to have a working transistor.

Of course, this isn’t a truly homemade transistor, it’s more of a DIY transistor conversion. The device appears to be functional, however it requires fairly high voltages to work, and only acts as a power amplifier instead of a voltage amplifier. Even so, it looks like an interesting way to experiment with transistors at home. I’d like to build one, and vary thickness of the insulator (scotch tape) to see what the results are. Anyone else have experience with this?

Make a series letters from the LED , Things to consider before making the sign of the LED array,
1) Use LED nodes.
2) Paint the top of the PCB with a dark color (black).
3) Note the LED specifications. In this experiment use a 5mm diameter LED nodes
that emit red, specification voltage of 3 volts.



The assembly of LED:
1) One letter composed at most 5 columns and 7 rows.
2) One column mostly composed by 6 LEDs are arranged series.
3) Then the fifth column are connected in parallel.
5) In a column consisting of 6 LEDs, Rx = 330 ohm, 5 LEDs, Rx = 560 Ohms, 4 LEDs, Rx = 680 Ohms
6) Every letter was given FCS9013 transistor amplifier.

Here is one letter LED scheme.



Medium picture below is the lay out of the 2-letter nameplate. To make the sign 8 letter, copied from a second stay this letter.



Example of LED on the letters A and B:


Rx first column letter B, 330 ohms. Rx second column, third, fourth, and fifth at 680 ohms.