November 2008 - Do It Easy With ScienceProg

The Great PLL Induction Heater Driver

Have you ever played with a manually tuned induction heater before? If you did, then you must know that how dull it could be… Oh, for those that didn’t know what the induction heater is, that is a key piece of equipment used in all forms of induction heating. An induction heater will technically operate at either medium frequency (MF) or radiofrequency (RF) ranges. Three main components form the basis of a modern induction heater, such as the power unit (power inverter), the word head (transformer), and the coil (inductor). This project is slightly different from the regular induction heater driver, as it will include the Phase Lock Loop (PLL) into it. A phase lock loop is a control system that can generate a signal, and it has a fixed relation to the phase of a “reference” signal itself. Since the phase lock loop circuit responds to both the frequency and the input signals phase, it raises or lowers the frequency of a controlled oscillator automatically until it’s matched to the reference in both frequency and phase. Overall, this PLL induction heater driver will be one of the magnificent projects that you’ve ever built!

Great method of PCB reverse engineering by using a Photoshop

Rriccibitti has sent us his latest work on reverse engineering of simple keypad circuit. The solution seems to be very simple but effective. He used a digital camera to take a picture of the printed circuit board and a photo editing software to track PCB traces with different colors. OK, for this one, he used Photoshop to have lots of valuable tools that make this work much more manageable. To be more specific, let us see what he’s done:

Circuit Diagram

A circuit diagram is also known as an electrical diagram, wiring diagram, elementary diagram, or electronic schematic. It is a simplified conventional symbolic representation of an electrical circuit. It shows the circuit components using easily understood symbols and the power and signal connections between the devices. The components’ arrangement and their interconnections on the diagram do not correspond to their physical locations in the finished device. Unlike a block diagram or layout diagram, a circuit diagram shows the actual wire connections being used. The chart does not in any way represent the physical arrangement of components. Circuit diagrams are used for the design, construction, and maintenance of electrical and electronic equipment.

Analog Circuit Design

Today’s modern circuit design is a bit of a conglomerate thanks to the availability of sophisticated process technologies that have made bipolar and CMOS (Complementary Metal Oxide Semiconductor), power and signal, passive and active components available, all on the same die. From this point on, it is up to the circuit designer’s ingenuity to assemble these components into the analog and/or logic building blocks that are deemed necessary to develop the intended system on a chip.