Basic Electronics and Tutorials

An accelerometer is a device that measures non-gravitational accelerations. These are accelerations produced by mechanically accelerating the accelerometer via its casing. Accelerometers can be used to measure vehicle acceleration.

Accelerometers can be used to measure vibration on cars, machines, buildings, process control systems and safety installations. They can also be used to measure seismic activity, inclination, machine vibration, dynamic distance and speed with or without the influence of gravity. - Accelerometer Wikipedia



MMA7260Q is a 3-axis accelerometer  from Freescale Semiconductor. This accelerometer can be used with an extension Library Mma7260q which simplifies some initialization values and tilt detection.

ADXL105 Lower-Noise Wider-Bandwidth Accelerometer - The ADXL105, a near-ideal kind of vibration sensor, eliminates significant problems with existing vibration sensors, such as piezoelectric and bulk capacitive sensors. Primary benefits derive from much lower cost, stable sensitivity as a function of frequency and temperature, ruggedness, and ease of use. Besides machine health and condition monitoring, it is particularly well suited for noise and vibration cancellation applications.

A beginner's guide to accelerometers - By measuring the amount of static acceleration due to gravity, you can find out the angle the device is tilted at with respect to the earth. By sensing the amount of dynamic acceleration, you can analyze the way the device is moving.

Society of Robots' tilt to servo control app - How does it work? Inside an accelerator MEMS device are tiny micro-structures that bend due to momentum and gravity. When it experiences any form of acceleration, these tiny structures bend by an equivelent amount which can be electrically detected

David T.'s motor balancing experiments - Using an oscilloscope to measure AC vibration signals generated by an accelerometer (from Dimension Engineering).

Simulates AC and DC circuits. Created by by Toon Van Hoecke at the Universiteit Gent. Try out small circuits and see response in Meters and Scope. Using the Java Applet Power.

Install the latest Java jre and use the IE browser. In Control Panel Java-Security add a site exception webphysics.davidson.edu. Then you can see the simulations. (2017 win 10 )

Physlets, Physics Applets,

Physlets are simple.  The graphics are simple; each Physlet is designed to deal with only one facet of physical phenomena, and does not incorporate very much in the way of data analysis.  This keeps Physlets relatively small—easing downloading problems over slow network connections—and removes details that could be more distracting than helpful.



Circuitbuilder simulates AC and DC circuits.  It was written by by Toon Van Hoecke at the Universiteit Gent.  Circuit Builder can be used in interactive mode (see above) or it can be scripted using JavaScript (see the demo pages). In order for scripting to work, Circuit Builder requires a Java 1.1 capable browser with JavaScript to Java scripting capability.

This was a Beta Hfe and Vce Measuring Instrument used in Incoming Inspection of Power Transistors made by me 16 years back.

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When a product has to be made small, the board real estate is limited or it has to be manufactured in large numbers.... SoC is the Answer. A Microprocessor evolved into a Microcontroller by packing many external chips into one chip. Now uC Card along with the other blocks like A-D, Port Drivers, Networking elements, Display Driver and other peripherals can be packed into one chip.

Some Power Supply and RF blocks cannot be easily added inside as they have a silicon processing more specific to their applications. Laser trimmed Instrumentation Op-Amps, high accuracy resistor arrays, high value capacitors, magnetics and supporting chips are placed outside on the PCB.

The SOC can pack Digital Chips, Memory, A/D, D/A converters, uC, RAM and Custom programmable areas. For more specialized communications, analog and power requirements; Special SoC types can tackle RF and Power management within a chip because of proprietary silicon processing expertise.

System on a chip - Wiki

"A system on a chip or system on chip (SoC or SOC) is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often radio-frequency functions—all on a single chip substrate. A typical application is in the area of embedded systems."



Programmable SoC offers an alternative to custom ASIC as you can make different products from the same chip, yet make products that are portable and low power. The software, pcb, user interface and support components has to be redesigned for every unique product. Many standard IPs are available for Design and Reuse.


Some of the early nxp 8031 variations had integrated a lot of outer chips like A/D, D/A display driver etc. This made Programmable Industrial Instruments/Gadgets possible with just a few external components. Now many variations are available from chip manufacturers, with more speed, memory and peripherals inside. Futuristic gadgets may be intelligent, interactive, networked and portable. The SoC chip makes it all possible, by integrating all product functions within it except the user interface.

SoC with a Color LCD driver, Wi-Fi, USB, RAM and Flash capabilities....at last you have a Computer in a Chip. Better still Web-Chip.

With 40 nm Stratix IV FPGAs you can reach new levels of system-on-a-chip (SoC) integration. Building on the advanced, proven Stratix III architecture, Stratix IV FPGAs deliver a high-density, feature-rich and high-performance core fabric. Combined with flexible I/Os, high-bandwidth transceivers, and memory interfaces,

PCB Thermal Design Care for Analog Circuit Stability - If you have a hot power chip near a DC analog circuit, the values will drift, take time to stabilize, this happens even if you use 1% MFR 100ppm. The impact is more if the heatsink is not used and vents and coolers are absent,

So in a PCB keep distance between heating power circuits and sensitive analog circuits, some times PCB tracks will carry heat to the Analog area, Hence keep sensitive analog circuits as plugin modules.



When you make a PCB try to orient all ICs in one direction, so also all diode and cap polarities, then it is easy to populate the parts, easy to verify and troubleshoot for production and testing.

High Frequency and RF Design of PCB

• Sharp bends in PCB tracks or wires will radiate away the RF energy, so do not have hairpin bends.
• RF or near RF multilayer PCB have 2 layers as ground plane and tracks in the layer in between, Faraday cage.
•  Electronic RF Product or System Design like  Communication Products.. Important rule "the first rule of connectors is that the best connector is no connector at all...". In RF the connectors and their placement needs extra care. At a frequency of 1 GHz, a short PCB track can become an Antenna !

Schematic Design Basics

• When we draw circuits we have to keep in mind the readability, the circuit should be laid out, according to the signal flow, the input output ports shown in the periphery of circuit.
• Drawing a neat circuit diagram will ensure a better design, lesser parts means greater reliability, simple solutions.

A well-drawn schematic makes it easy to understand how a circuit works and aids in troubleshooting; a poor schematic only creates confusion.

Product Design Mockup and Prototypes

• Make a 3D mockup of the final product, both the box and the PCB with components before PCB done.
• The product with the PCbs, transformer and other panel components should fit in the box it was intended for, or the cabinet that was designed for the Product. To make sure make a Mock-up Product - 3D and display. Even if you have all documents and drawings in place.
• Make sure of IC pin numbers, size and packages and indicate in circuit like 40 pin dip before going to PCB. Also check every EDA symbol in your software with the company datasheet to make double sure.
• Do not mix mechanical and electrical connections, these leads to failures and frequent need of repairs and service. this is a rule, more so for power connectors.
• Strain relief prevents mechanical stress from reaching the connector joints/spring metal. The wire terminations are also cushioned by strain relief.
• The PCB and Product Engineering should ensure that the mechanical stress or load is not a job/function/role of the connector. At higher currents a small contact resistance can generate a lot of heat, worsening the contact further, similar to thermal runaway of Power Transistors.
• When using a double or multi layer pcb make one layer a ground plane, all decoupling caps ground linked to it.
• Reinforce copper tracks on PCB with a copper wire when it needs to carry more current, tinning may improve a bit.