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Is it possible to build a home-made Tesla Coil?

noreply@digikey.com — Fri, 17 May 2013 16:43:05 GMT

If my understanding is correct, one needs to have a firm grasp of alternating current, inductors, capacitors, and the concept of resonant circuits and be able to use software (Tesla coil simulator) to simplify the actual calculations.

Assuming I were to begin by with a spark gap coil design (as it’s the simplest in theory), what is the best type of transformer to charge the primary tank capacitor?

Is a solid-state type easier for the first timer to tackle?

Thanks,
Zigg

Learn about basic electronics for free

noreply@digikey.com — Sun, 06 Nov 2011 16:56:15 GMT

Want to learn about basic electronics? I have found a site that offer's free online electronics training. www.learn-about-electronics.com

Hazardous Classified Locations

noreply@digikey.com — Wed, 22 May 2013 13:19:31 GMT

The National Electrical Code (NEC) defines hazardous locations as those areas "where fire or explosion hazards may exist due to flammable gases or vapours, flammable liquids, combustible dust, or ignitable fibers or flyings."

Hazardous Location Types

Class I Locations

According to the NEC, there are three types of hazardous locations. The first type of hazard is one which is created by the presence of flammable gases or vapours in the air, such as natural gas or gasoline vapour. When these materials are found in the atmosphere, a potential for explosion exists, which could be ignited if an electrical or other source of ignition is present. The Code writers have referred to this first type of hazard as Class I. So, a Class I Hazardous Location is one in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable. Some typical Class I locations are:

Petroleum refineries, and gasoline storage and dispensing areas;
Dry cleaning plants where vapors from cleaning fluids can be present;
Spray finishing areas;
Aircraft hangars and fuel servicing areas; and
Utility gas plants, and operations involving storage and handling of liquified petroleum gas or natural gas.
All of these are Class I . . . gas or vapor . . . hazardous locations. All require special Class I hazardous location equipment.

Class II Locations

The second type of hazard are those areas made hazardous by the presence of combustible dust. These are referred to in the Code as "Class II Locations." Finely pulverized material, suspended in the atmosphere, can cause as powerful an explosion as one occurring at a petroleum refinery. Some typical Class II locations are:

Grain elevators;
Flour and feed mills;
Plants that manufacture, use or store magnesium or aluminum powders;
Producers of plastics, medicines and fireworks;
Producers of starch or candies;
Spice-grinding plants, sugar plants and cocoa plants; and
Coal preparation plants and other carbon handling or processing areas.

Class III Locations

Class III hazardous locations are areas where there are easily-ignitable fibers or flyings present, due to the types of materials being handled, stored, or processed. The fibers and flyings are not likely to be suspended in the air, but can collect around machinery or on lighting fixtures and where heat, a spark or hot metal can ignite them. Some typical Class III locations are:

Textile mills, cotton gins;
Cotton seed mills, flax processing plants; and
Plants that shape, pulverize or cut wood and create sawdust or flyings.

Reference: http://www.osha.gov/doc/outreachtraining/htmlfiles/hazloc.html

LED Dimmer best quality

noreply@digikey.com — Thu, 17 Jan 2013 16:27:01 GMT

I am installing about 80 watts of LED lighting in a public institution and would like the best dimmer. I am aware of SuperBrite but wonder about their durability.

IF DESIGN RESOURCES

noreply@digikey.com — Fri, 17 May 2013 02:05:02 GMT

I want to design a two or three state 455 kHz IF amplifier. I cannot find any information relating to IF design, and the selection if IF transformers. I'm not designing an AM Radio, but I have a specific design that would make great use of a few stages of IF... Any resources you know of?????

Smartphones Shun Small With Ever-Bigger Screens

noreply@digikey.com — Thu, 08 Sep 2011 00:32:46 GMT

The Android-running Samsung Infuse wowed us with its 4.5-inch display at CES.

Photo: Jon Snyder/Wired.com

For much of the mobile world, the emphasis is smaller, slimmer and lighter. But when it comes to smartphones, it seems bigger is better.

A growing number of smartphone manufacturers are trying to distinguish themselves from the competition by giving their phones ever more spacious screens. It was definitely a trend at the big IFA consumer electronics show in Berlin, one we first spotted at CES.

The Samsung Galaxy S II LTE phone, Samsung Galaxy Note and HTC’s Windows Phone 7–running Titan all featured relatively ginormous 4.5-inch to 5.5-inch displays. The burrito-shaped Sony Tablet P follows that trend times two: It features a pair of 5.5-inch displays that open like a clamshell. Even Apple appears to be getting in on the act: The next iPhone reportedly sports a larger display.

At CES earlier this year we saw a number of large-screened beauties take the stage, including the 4.5-inch Samsung Infuse. Some 4.3-inchers also have appeared, like the Motorola Photon 4G and upcoming Motorola Droid Bionic.

And last year, the Dell Streak blurred the line between smartphone and tablet with its 5-inch screen.

There’s some hard data to back up the trend, too. The NPD Group found sales of smartphones with screens 4 inches or larger are definitely increasing. At the end of last year, 24 percent of smartphone handsets sold had a screen size of 4 inches or more. The number of phones with screens 3.4 inches or smaller dropped from 63 percent to 36 percent between 2009 and 2010.

“The explosion in web and video content available for smartphones has caused consumers to rethink their phones’ sizes,” Ross Rubin, NPD’s executive director of industry analysis, said in a statement. “Larger displays offer a richer media experience, as well as a roomier surface for onscreen keyboards.”

Rubin told Wired.com the Samsung Infuse has done relatively well at AT&T. As long as the increase in a device’s screen size doesn’t come with an overall increase in the size of the phone, we’ll continue to see more people adopt phones with larger displays.

And that raises an interesting point: Even if you need a screen that big, can you still call it a smartphone? No, said Ken Dulaney, an analyst at Gartner.

“We believe that a smartphone ends and a tablet begins at 4.2 inches diagonal,” Dulaney said. “A 4.5-inch device is a small tablet, in my opinion.”

A better definition might be how conveniently you can carry something that big.

“The question becomes what is the maximum screen size one can put in their pocket, which is the limiting factor,” Rubin said. “The Samsung Galaxy Note has a 5.3-inch screen. Samsung claims that’s the largest that can be accommodated in a pocket. I think that’s a tablet, not a phone.”

Whatever you call it, many manufacturers believe a larger display is a great way to distinguish a product from the competition because, let’s face it — a lot of smartphones look alike.

“Today’s smartphones are pretty difficult to distinguish when it comes to the customer actually looking at them in stores. Increasing the screen is a clear example of manufacturers trying to differentiate rather than following the established product classes,” Geoff Blaber, an analyst at CCS Insight, told MacWorld.

The screens aren’t only getting bigger, they’re getting sharper. Samsung has been developing miniature full-HD screens with its Super AMOLED Plus technology. We’ll probably see displays 5 inches or bigger with 1280 × 720 resolution by the end of the year.

The bigger screens reflect how a lot of people use their phones, which aren’t so much phones as media-consumption devices. People are more likely to use their phones to watch movies, stream videos and play games during the daily commute, that boring staff meeting or any other time the boredom is otherwise unbearable.

Interested? Keep reading on Wired

What consumer technology will make the biggest splash at 2012 CES?

noreply@digikey.com — Thu, 29 Dec 2011 20:28:23 GMT

Last year it was mostly products related to 3D TV. This year I am not sure. What do you think?

USB Port Protection

noreply@digikey.com — Tue, 21 May 2013 07:11:22 GMT

The Protection of USB 2.0 Applications

USB Port Protection

The USB-Interface might be the most distributed PC interface in the world. The usage in industry applications is more and more common. Let’s have a closer look to the special environmental conditions of industry applications.

That there are real concerns regarding the robustness against EMI and ESD is written in Intel’s “High Speed USB Platform Design Guidelines”. Intel recommends the usage of a common mode choke for EMI suppressions and another component for protection against ESD pulses.

Würth Elektronik offers all these types of products.

- The WE-CNSW common mode choke was developed for EMI suppression on high speed signal lines

- For ESD suppression the TVS diode arrays WE-TVS with very low capacitances (<2pF) or the ESD Suppressors WE-VE (capacitances down to 0.05pF) are your preferred choice.

But for outstanding EMI behaviour it is absolutely necessary to protect the power supply (V_bus) as well. A lot of design engineers forget this important point and wonder themselves when their product don’t pass all the tests in an EMI lab.

Two typical schematics for optimized protection of one or two USB ports are shown below:

With one TVS diode array WE-TVS you can fully protect two USB lines. All four signal lines as well as the common power supply are well protected. For further optimization, i.e. to filter incoming common mode noise as well as differential mode noise from USB line, a LC filter is built with the common mode choke WE-CNSW and the capacitors. For power supply lines very good noise suppressions can be eached with a chip bead ferrite, like the Würth Elektronik WE-CBF series.

Single line protection components like ESD suppressors series WE-VE also have to be connected from signal line to GND.

For power line protection it is not necessary to use a low cap ESD suppressor, you might prefer a standard SMD varistor which can withstand higher surges and higher transient energies.

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

About TVS Diodes

Würth Elektronik launched the TVS diodes array series called WE-TVS. These TVS diodes arrays include three main functions:

- protection against ESD pulses according to EN 61000-4-2

- protection against surge pulses according to EN 61000-4-5

- protection against EFT pulses according to EN 61000-4-4

WE-TVS series are high performance designed TVS diode arrays which include surge rated diodes. They are the best choice to protect high speed data lines like USB 2.0, DVI or LAN from over-voltages. The WE-TVS series exceeds the requirements outlined in EN 61000-4-2. Due to their ultra low capacitance (<2.0 pF) they are nearly invisible on the signal lines.

About ESD Suppressors

The ESD suppressors are special raised varistors with a low and defined intrinsic capacitance. Würth Elektronik has three different series:

- WE-VE standard series: Capacitances of 1pF to 120pF and voltages from 5V to 24V

- WE-VE “ULC” series: Capacitance of 0.2pF, suitable for signal lines up to 12V

- WE-VE femtoF series: Capacitance of 0.05pF and rated voltages of 6V, 14V and 26V

For the first two series are also four-fold array packages available.

Why ESD Protection?

Since the first electronic developments, all the parts are subjected to electrostatic discharge. ESD events have peak voltages up to 30kV and therewith they are very dangerous for all kind of integrated circuits.

However, some state-of-the-art ICs are protected against ESD pulses but real world conditions show daily that an additional protection device is indispensable. On the one hand to have the whole board ESD free and on the other hand to develop more reliable products to satisfy the needs of your customers.

Why EMI Suppression?

With the increase in electronic/electrical products and the need to have wireless connectivity in today’s global markets, there is an increased requirement to ensure that your product is immune to the impacts caused by both the intentional and un-intentional RF environment. Only if you consider now which EMI phenomena impacts on the product, will you be able to design in the appropriate protection and reduce time to market.

In addition, the product must not generate excessive levels of EMI and this is typically assessed by an EMC Test Laboratory, and should the product fail then costs to implement remedial work will increase aggressively.

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Different Protection Devices for Different Requirements

There are four different TVS diode arrays and five different ESD Suppressors available:

Order Code	Package	Pin Conf.	I/O / VDD Lines	V_RWM	C_IN	I_PP	V_ESD	V_{Cl ESD}	VDD can float
824 011	SOT23-5L	1	2/1	5V	2.0 pF	12 A	20 kV	13 V	NO
824 015	SOT23-6L	2	4/1	5V	2.0 pF	12 A	20 kV	13 V	NO
824 001	SOT23-6L	2	4/1	5V	1.0pF	5A	15kV	14V	NO
824 014	SOT23-6L	3	4/1	5V	0.5 pF	4A	16kV	12V	YES
823 07 050 029	0402	4	1	5V	0.2 pF	-	8kV	17V	-
823 06 050 029	0603	4	1	5V	0.2 pF	-	8kV	30V	-
823 81 120 029	0612	5	4	12V	0.2 pF	-	8kV	30V	-
823 17 06	0402	4	1	6V	0.05 pF	-	8kV	40V	-
823 16 06	0603	4	1	6V	0.05 pF	-	8kV	40V	-

Pin Configuration 4

Pin Configuration 1

Pin Configuration 2

Pin Configuration 3

Pin Configuration 5

How to find the Suitable Part?

- You have supply voltage to connect for rail-to-rail clamping

--> take TVS diode

- You don’t have supply voltage or do prefer ceramic components

--> take TVS diode where VDD pin can float or take WE-VE ESD suppressor

- Which maximum capacitance can you add to your data lines to pass the eye pattern test?

--> for USB 2.0 line capacitances up to 5pF shouldn’t cause any trouble

- What’s the maximum expected ESD voltage that can occur?

- Do you want to protect one or two USB lines? However, connecting one USB data line with two I/O

ports of TVS diode lets you get a better performance --> select array type

Answer all these questions and you will find the most suitable part for you. We recommend for one USB 2.0 port #824011 and for two USB 2.0 ports #824015 . Designers preferring single line components may choose p/n #82307050029 or #82306050029 .

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Eye Pattern Test

After making a choice of protection element you have to ensure that your whole interface design meets the requirements of USB specification. Therefore you can use our protection devices with a small capacitance which is nearly invisible on the signal lines.

Port 1: D+

Port 1: D-

Port 2: D+

Port 2: DEye

Pattern test without any protection component placed on two USB 2.0 differential signal lines

Port 1: D+

Port 1: D-

Port 2: D+

Port 2: DEye

Eye pattern test with TVS diode WE-TVS p/n 824 015

The eye pattern test shows that the WE-TVS do not disturb the USB 2.0 signal. You get the same results with our other listed TVS diodes and with the ESD suppressors as well. The following table shows the cutting edge ultra low capacitance technology of Würth Elektronik. This technology enables a channel to channel capacitance which is almost invisible at normal operating conditions.

Order Code	Order Code Package	I/O	V_RWM	C_IN	C_X
824 015	SOT23-6L	4	5	2pF	0,1pF
Competitor S	SOT23-6L	4	5	3pF	1,5pF
824 001	SOT23-6L	4	5	1pF	0,1pF
Competitor P	SOT23-6L	4	5	3pF	1,5pF
I/O		Number of I/O lines the TVS-Diode can protect
V_RWM		Max. reverse working voltage
C_IN		Input capacitance at I/O pin via. GND (VIN = 2,5V, VDD=5V)
C_X		Input capacitance between I/O pins (VIN = 2,5V, VDD=5V)

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Testing the Protection Level of ESD Protection Devices

The easiest way to measure the protection level is to apply an ESD pulse to your electronic circuit with the ESD protection device and measure the peak voltage of this ESD pulse before and after the protection device. But this way carries out different problems.

Due to high frequency and wide range of ESD pulse (few MHz to some GHZ) high frequency refractions will occur during the measurement. The absolute peak voltage and the spike voltages during the refractions are an indicator for better and worse protection, but you cannot indicate the definitive clamping voltage. And by the way, this is not a reliable and repeatable measurement!

Engineers being familiar with semiconductor products do know the TLP measuring method. The TLP (transmission line pulsing) method is an accurate measurement system which allows - due to all measurements are done in a 50Ω-System - repeatable and very accurate measurements.

A defined current impulse (left) is charged into the protection component and the resulting voltage across it is measured (middle). This procedure is repeated with increasing TLP currents. As a result you get the TLP curve (right).

TLP measurement system with corresponding TLP curve

This measurement can be done for VDD and I/O pins. The lower the voltage you measure, the better is the protection device and therewith the reliability of your electronic circuit.

Thanks to the built in snap-back technology, Würth Elektronik TVS diodes have the lowest ESD clamping voltage on the market. Compared to competitors’ products, the WE-TVS do outperform them clearly! This you can see with a short view at the TLP curves.

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Order Code	Package	I/O	V_RWM	V_Cl,IO	V_Cl,VDD	V_ESD	C_IN	I_PP
824 015	SOT23-6L	4	5	12	7,5	12kV	2pF	12A
Competitor S	SOT23-6L	4	5	22	15,5	15kV	3pF	12A
824 001	SOT23-6L	4	5	14	9	8kV	1pF	5A
Competitor P	SOT23-6L	4	5	28	19	8kV	3pF	6A
I/O	Number of I/O lines the TVS-Diode can protect
V_RWM	Max. reverse working voltage
V_Cl,IO	ESD clamping voltage at I/O pin (IEC 61000-4-2, contact mode at 6kV)
V_Cl,VDD	ESD clamping voltage at VDD pin (IEC 61000-4-2, contact mode at 6kV)
V_ESD	Max. withstanding ESD pulse (IEC 61000-4-2, contact mode)
C_IN	Input capacitance at I/O pin via. GND (VIN = 2,5V, VDD=5V)
I_PP	Max. Withstanding surge current (8/20μs)


TLP Curve of different parts for VDD	TLP Curve of different parts for I/O lines

Recommended Layout for Single USB Port

The two differential signal lines (D+ and D-) are routed from connector to TVS-Diode (p/n #824 011 ) and via a common mode choke (p/n #744 232 090 ) to the USB controller as shown on the left picture below. This results in an awesome ESD protection and EMI suppression of both data lines.

VBUS is routed like the signal line, but instead of the common mode choke a chip bead ferrite (p/n #742 792 641 ) is used. After the chip bead you may add a capacitor and a second chip bead as well to get the highest possible EMI suppression effect.

For very sensible IC’s and / or high reliable applications you can get an optimized ESD suppression effect if you double contact a four-fold TVS array (p/n #824 015 ) like shown on right picture.

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications


Protection of single USB port	Double protection of single USB port
	Designers preferring single channel components can also use the ESD Suppressors WE-VE. The connection has to be carried out from D+ / D- to GND. The other parts are connected in same way as above.
Protection of single USB port

Recommended Layout for Double USB Port

According to single USB port protection the routing is very similar. Use exactly the same parts as for single port protection and the protection level will also be the same.

Protection of double USB port

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Bill of Material:

In this application note the following parts are used:

TVS-Diodes WE-TVS:

824 011: Protection of 2 I&O lines and VDD line: Size SOT23-5L | 2pF C_I/O | 5V V_RWM | 5A I_PP

824 015: Protection of 4 I&O lines and VDD line: Size SOT23-6L | 2pF C_I/O | 5V V_RWM | 5A I_PP

ESD Suppressors WE-VE:

823 07 050 029: Size 0402 | 0.2pF C_typ | 5V V_RWM | 17V V_CL

823 06 050 029: Size 0603 | 0.2pF C_typ | 5V V_RWM | 30V V_CL

Common Mode Chokes WE-CNSW:

744 232 090: Size 1206 | 370mA IDC | 300 mR_DC | 90W Impedance

Chip Bead Ferrites WE-CBF:

742 792 641: Size 0603 | 2 000mA I_DC | 150 mR_DC | 300W Impedance

USB-Connectors WR-COM:

614 008 260 21: USB Typ A Connector | THT | Dual stacked

614 004 135 023: USB Typ A Connector | THT | Vertical

A p p l i c a t i o n N o t e

The Protection of USB 2.0 Applications

Interface Design Kit

For an easy design of interfaces Würth Elektronik has launched a special Interface Design Kit. This design kit includes a design guide for USB 1.0 to USB 2.0, CAN, Ethernet, VGA, DVI, RS232 and RS485 interfaces and all the components used. These are ESD Suppressors, SMD Common Mode Chokes, Chip Bead Ferrites, LAN Transformers and the corresponding Connectors.

In total are 35 different passive components with 235 parts and 4 evaluation boards in. The colour scheme makes it easy to locate the suitable parts for your application. Just follow the specific application colours and arrange your needed parts.

For each application you find a simple block schematic where you see how to place the different components to get the best result...try it!

-Application Notes & Technical Reports-

-follow us on techXchange-

This document was generated from the following discussion: USB Port Protection

MX150L™ 19427 Series

noreply@digikey.com — Mon, 20 May 2013 20:17:55 GMT

Subtitle:

0.230" (5.84mm) Pitch Shrouded Through Hole Right Angle Male Pin Connector Headers

Supplier:

Molex Connector Corporation

Description:

The MX150L™ sealed connector system is designed to meet the need for a rugged, environmentally sealed connector system supporting both low-level signal applications as well as power applications up to 40.0A, from on-engine automotive and marine applications to off-road construction equipment applications.

Please limit comments in this discussion to this series.

TMS320C6713 Evaluation Board 701895

noreply@digikey.com — Mon, 20 May 2013 09:43:47 GMT

Subtitle:

701895 DSP Starter Kit (DSK) for the TMS320C6713

Supplier:

Spectrum Digital Inc

Description:

The 6713 DSP Starter Kit (DSK) is an all-in-one evaluation platform for the TMS320C6713 Digital Signal Processor from Texas Instruments. It includes a target board that can be used as a reference design for interfacing the DSP to common devices such as SDRAM, Flash and a codec as well as a special introductory version of TI's flagship Code Composer Studio development tools. An on-board JTAG emulator allows debug from Code Composer Studio through your PC's USB port.

This kit contains everything you need to get started with TI DSPs. It can also be used with the full version of Code Composer Studio and an external JTAG emulator.

Please limit comments in this discussion to this series.