FLIP FLOP CIRCUIT

You’re a newbie in electronics and you need to practice your electronics knowledge and then I suggest you to build this LED Flasher (Flip-Flop). This circuit is very simple and very easy to understand…

INTRODUCTION:

Flashing circuits are very interesting. They grab your attention and can be used in many applications. They consume very little energy and a single cell can last as long as 12 months. This is the simplest circuit capable of alternately flashing two LEDs. 

SCHEMATIC DIAGRAM:

Smoothing

Smoothing is performed by a large value electrolytic capacitor connected across the DC supply to act as a reservoir, supplying current to the output when the varying DC voltage from the rectifier is falling. The diagram shows the unsmoothed varying DC (dotted line) and the smoothed DC (solid line). The capacitor charges quickly near the peak of the varying DC, and then discharges as it supplies current to the output. 

Single diode rectifier

A single diode can be used as a rectifier but this produces half-wave varying DC which has gaps when the AC is negative. It is hard to smooth this sufficiently well to supply electronic circuits unless they require a very small current so the smoothing capacitor does not significantly discharge during the gaps. Please see the Diodes page for some examples of rectifier diodes. 

Bridge rectifier

A bridge rectifier can be made using four individual diodes, but it is also available in special packages containing the four diodes required. It is called a full-wave rectifier because it uses all the AC wave (both positive and negative sections). 1.4V is used up in the bridge rectifier because each diode uses 0.7V when conducting and there are always two diodes conducting, as shown in the diagram below. Bridge rectifiers are rated by the maximum current they can pass and the maximum reverse voltage they can withstand (this must be at least three times the supply RMS voltage so the rectifier can withstand the peak voltages). Please see the Diodes page for more details, including pictures of bridge rectifiers. 

Rectifier

There are several ways of connecting diodes to make a rectifier to convert AC to DC. The bridge rectifier is the most important and it produces full-wave varying DC. A full-wave rectifier can also be made from just two diodes if a centre-tap transformer is used, but this method is rarely used now that diodes are cheaper. A single diode can be used as a rectifier but it only uses the positive (+) parts of the AC wave to produce half-wave varying DC.

Transformer + Rectifier + Smoothing + Regulator

The regulated DC output is very smooth with no ripple. It is suitable for all electronic circuits.

Transformer + Rectifier + Smoothing

The smooth DC output has a small ripple. It is suitable for most electronic circuits.

Transformer + Rectifier

The varying DC output is suitable for lamps, heaters and standard motors. It is not suitable for electronic circuits unless they include a smoothing capacitor.

printed circuit

There are various methods to remove these minute traces of gold from printed circuit boards, processors, and other peripherals. First requirement is milling of the PCB to expose the gold in the chips. Various methods can be used to break or mill the printed circuit board. The easiest and cheapest way of extracting gold from Printed Circuit Boards would be to mechanically cut off the tops of the microchips and carry out forging to melt all the metal that is present inside the chip. Gold has a higher molecular weight which makes it denser and heavier than other metals. Hence, any of the traditional methods of separation such as skimming, draining lighter metals or settling tank for heavier metals can be used
There’s another method for extracting gold from printed circuit boards in which, the Printed circuit board scrap is treated with one part concentrated nitric acid and two parts water at 70-80°C for 1 hour, which dissolves the base metals. As a result, it liberates the chips from the PCB
Note: We will refer printed circuit boards as PCB in short hereafter.
Coming back to the process, after solid and liquid components are separated, the chips along with some metallic residue and Ti02 precipitate are mechanically crushed. This liberates the base and gold metal present within the protective plastic or ceramic chip
The base metals in this pulverized product are further dissolved by leaching with the same composition of nitric acid and water. The remaining solid residues, crushed chips and resin and solid particles of gold are treated with aqua regia by leaching process at varying and suitable times and temperatures. Gold is then precipitated from the leaching product with ferrous sulphate
There are plethora of options to extract gold from processors, PCBs, and other similar things. For extracting gold from printed circuit boards even in minute quantities, you may require a large number of PCBs. A metric ton would approximately have 80 to 1600 grams of gold. With evolving technology and development in PCB design, the amount of gold used for fabrication and creation of components is reduced. Moreover, before extraction you need to figure out the potential earnings involved with the amount of gold available on these PCBs, so that the cost of retrieving the gold does not exceed the cost of the gold obtained
More so, there are many more things to be considered, before you try anything of this sort, and try to gain handsome profits out of all your hard work. Hence, before extracting Gold from Printed Circuit Boards, you need to do an economic assessment on the value of the recoverable gold to make the process worthwhile
Various chemicals have the ability to remove and refine gold such as sodium cyanide and sodium meta nitro benzene sulphonate. Sodium cyanide is the cheapest available unless you can find calcium cyanide. However, the overall methodology is fairly complex in comparison to the other conventional ways. There are other ways of even using chemicals for Extracting Gold from Printed Circuit Boards. Looking for the Cheapest Way of Extracting Gold from Printed Circuit Boards – follow the link in resource box