Kirlian photography – a simple way of taking it

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by Robert Gawron:

Kirlian photography is an interesting photographic technique of capturing corona discharge of objects. The images basically contain only edges in a form of blue glow. Note: one of those photos is visible in “The X files” intro – read the whole article to know why!

In this post I will present my minimalist approach with common materials and without complicated construction. The results aren’t that good as with more complex setups, but I think that they are still really interesting.

Kirlian photography – a simple way of taking it – [Link]

CRYDOM – solid state relays from specialists

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Silent operation, immunity against mechanical shocks and magnetic field and other factors make a solid state relay the best choice for many applications.

Where to start? We´ll try to name “pluses” of solid state relays – SSR:

  • long lifetime, no moving parts, no contact burning
  • silent operation, very desirable for commercial and medical applications
  • minimum electrical noise thanks to a possibility of zero-crossing switching
  • easy control (interfacing) and minimum energy consumption to control
  • resistance to shocks and vibrations, installation in any position
  • fast switching (approx. 0.1 ms)
  • low weight
  • immunity to outer magnetic field (usable near powerful motors,…)

Some disadvantage of SSR is, that they generate more heat when conducting a current through “contacts”, than classic EMR. But this is dependent on a switched current. On the other hand – power consumption of the SSR itself is minimal in comparison to EMR of a similar size.

From above mentioned features result, that SSRs are a great choice everywhere, where it´s necessary to switch frequently and/or also to change rotation of motors (integrated in a single component). SSRs are also maximally suitable for switching of DC currents (solar applications, batteries,…) as they don´t suffer by arcing and contact wearing like classic EMRs (DC arcing is much more difficult to extinguish than the AC one). Much longer lifetime in comparison to EMRs result in very low operation/ service costs and significantly eliminates losses caused by eventual downtimes.

If we allured you to SSR, than it´s certainly worth to take a look at products of a leading producer in this field – výrobky spoločnosti CRYDOM, which specializes for development and production of SSRs already for over 40 years. Among novelties in our stock can be found Crydom SSR for PCB in SIP and miniSIP packages, panel mount types, as well as types for a DIN-rail mount. Their basic features are very similar, they differ mainly in max. voltage and current, which they´re able to switch.

Practically each SSR Crydom is available for switching of AC or DC current and also in an “R” version (random switching in any phase of AC voltage) or „ZCD – zero crossing“ switching in “zero” (suitable for minimizing of switching noise).

Detailed specification can be found in the datasheets at jednotlivých typoch and a help at selecting will provide you documents Crydom overview, Crydom product guide, Crydom Selecting SSR and Crydom motion control. The „SSR-the inside story” document is intended for those of you, who like to understand components deeply.


CRYDOM – solid state relays from specialists – [Link]

Brainboard v2: Demon of CNC controllers

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3D Printers, CNC Mills, Laser cutters, Pick n Place robots…Brainboard v2 will rule them all!

Brainboard v2 is a modular CNC controller board based on LPC1768/69 Cortex-M3 chip. Due to its modular design it allows easier upgrades as per requirements and easy replacement if there is any broken part. It runs on open source Smoothie modular firmware and is targeted at 3D Printers, Laser cutters, CNC Mills, Pick and Place and other small or Mid-size CNC machines. Upgrade your machines for higher performance and features.

Brainboard v2: Demon of CNC controllers – [Link]

Using RFM69CW instead of RFM12B

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Martin writes:

The rumors for RFM12B’s end-of-life two years ago seem to have been highly exaggerated now and the popular RF module is still available in abundance. HopeRF has introduced a pin-compatible upgrade, the RFM69CW. The module itself offers improved sensitivity and range compared to the RFM12B (+30%) at the cost of increased power consumption, making it probably a good choice for the receiving end (RFM2Pi), and probably less suited for low power battery operated nodes. The new module supports RSSI for those interested in measuring it.

The new module is more power hungry, and simply replacing a RFM12B on the RFM2Pi v2 or a Funky v3 with it didn’t work; The boards browned out so I had to swap C4 and C7 on the RFM2Pi with 10uF caps and populate the 0805 10uF on Funky v3’s boost regulator circuitry to get it to work. I’ll ship the boards with these refinements from now on so that they are compatible with both the RFM12B and RFM69CW.

[via]

Using RFM69CW instead of RFM12B – [Link]

Improved Silicon-Substrate LEDs Address High Solid-State Lighting Costs

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by Steven Keeping @ digikey.com:

The dominant technology for today’s high-brightness LEDs is gallium nitride (GaN) on sapphire or silicon carbide (SiC) substrates. These materials are popular because the resultant LEDs are bright, efficient, and last a long time. However, the chips are tough to manufacture and package into useable devices, multiplying the cost of end products that use them as light engines. Although prices have plummeted in recent years, LED lighting is still considerably more expensive to purchase than traditional alternatives. This initial expense is cited as a major factor slowing the acceptance of solid-state lighting (SSL).

A pioneering group of manufacturers has worked hard to reduce the cost of high-power LEDs by replacing the sapphire or SiC substrate with silicon (Si), the material routinely used to manufacture most electronic chips (“ICs”). The key benefit is a very-low-cost supply of wafers and the opportunity to use depreciated 8-inch wafer fabs for LED manufacture. Combined, those concepts enable a dramatic reduction in LED prices, overcoming consumer objections.

Improved Silicon-Substrate LEDs Address High Solid-State Lighting Costs – [Link]

MCU blends low power and high performance

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by Richard Quinnell @ edn.com

Texas Instruments has launched the MSP-432, a Cortex-M-based microcontroller that aims at providing developers with a higher-performance upgrade path for MSP-430 users while still retaining low-power operation. The 32-bit processor uses an M4F core with FPU and DSP extensions, achieving a CoreMark score of 3.41/MHz and a certified ULPBench score of 167.4, among the highest in its performance class.

The device can operate at full speed down to a supply of 1.62V, simplifying direct sensor interface. It specs an operating current of 95 µA/MHz and a sleep mode current of 850 nA with its real-time clock running. The device also contains a number of architectural features that support reduced power consumption while boosting performance.

MCU blends low power and high performance – [Link]

Diodes – Types and Applications

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In semiconductor and electronics industry, a diode is a widely used discrete component. It is a significant element in many electronic circuits and applications ranging from low power signal circuits to power rectification. Based on the functions and ratings, there are different types of diodes. However, all semiconductor diodes contain a PN junction to perform their basic operation.

Diodes – Types and Applications – [Link]

Automatic Tea Maker

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by 24Eng @ instructables.com:

I am scatterbrained. I like to drink hot tea. Oversteeped tea gets bitter. I am easily distracted.

The natural choice was to (over)engineer something with inexpensive hobby-grade electronics. Automatic tea timers are hardly new and people have made them from discarded toasters and K’Nex which I have a lot of respect for. People on this site have been making them with Arduinos and Servos for a long time so I’m hardly the first. This project has three major differences though.

Automatic Tea Maker – [Link]

3D Printed Desktop CNC mill

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by Elektron8 @ instructables.com:

Welcome to this project. The CNC UNO is a small desktop CNC Mill that can be used for hobby engraving and routing, PCB milling and education. It is mainly made with 3D Printed ABS plastic parts and plywood. Before starting this project, please observe that this machine is not intended for precision work nor for cutting hard materials like metal. As the machine parts are made of plastic and wood, the machine will flex under heavy load and that is why this project is for fun rather than any serious application. That said, it is a great little machine for hobbyists that want something to play with without having to spend a fortune.

3D Printed Desktop CNC mill – [Link]

Maintenance-free lead batteries Panasonic will surprise by their lifetime

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When observing basic rules will the top quality AGM VRLA batteries last you up to 15 years – we will advise how.

This description could start by a long list of technical improvements of Panasonic batteries. thanks to which they gained a stable place on the top of development in this segment (AGM, expanded positive grid. additives for regeneration from a deep discharge, self-extinguishing container material,…).

However those are things, which can be easily checked up from available internet source or even better from satisfied users. Instead of it, we better bring you a few advices for usage of VRLA/ SLA batteries to serve you as long as possible: