The Kynix Blog

Detecting temperature is an important function of skin. Snakes can use their skin to track warm-blooded prey, even in the dark. Now a highly sensitive, flexible sensor film could also make this characteristic available for robots and prosthetics. Whether in factories, the office or the kitchen: Robots continue to encroach on various aspects of our lives. When it comes to safety, that increases requirements for the “man-machine interface” considerably. Which is why developing sensitive robot skins has become a hot topic in robot research. After all, “collisions” can only be avoided if you can “see” your counterpart—as quickly and accurately as possible. Methods for doing so range from image processing using mechanical devices to contact-free sensor solutions. For example, scientists at the Technical University of Munich (TUM) have been working on artificial skin made of small hexagon plates with infrared, temperature and acceleration sensors. The infrared sensors register when things come close to the robot. Researchers at ETH Zurich and the California Institute of Technology (Caltech) are pursuing a more natural approach. Their temperature sensor is based on the plant material pectin. Like the snake’s extremely sensitive pit organ that can sense a mammal’s warm body up to a meter away, it can precisely measure temperatures to one hundredth of a degree. That is twice as sensitive as human skin.(A highly sensitive sensor film for robots measures temperatures with an accuracy of one hundredth of a degree. .)(Image: Caltech) “Cyber wood” as a temperature sensorDiscovering the artificial “snake organ” was actually a coincidence. It turns out that the electrical conductivity of cell walls in trees depends on temperature. That is because of the plant material pectin, which can also be used in the kitchen as a gelling agent for puddings and jams. Measurements that were taken on a type of “cyber wood” made of pectin and carbon nanotubes revealed that the higher the temperature, the more free calcium ions were formed at the contact points between two sugar molecules. Electrical conductivity increases proportionally. That is how the sensor idea was born. All that was missing was the “skin”. The answer: A 20-micrometer-thick film made of simple pectin gel laced with a calcium solution. Safe human-robot collaborationInitial testing revealed that the ultrathin transparent film that can be formed into nearly any shape can measure temperatures from 10 to 50 degrees Celsius with a precision of one hundredth of a degree. Supposedly, the “prey” that was used was a teddy bear—fresh from the microwave. To spatially resolve hot or cold sensations like human skin, researchers attached several electrodes along the long and short sides of a piece of “skin” measuring 25 square centimeters. The resulting grid made it possible to determine the position of temperature changes at specific locations. The “snake skin” is extremely easy to make and is more robust and less prone to interference than existing flexible temperature sensors equipped with transistors. After improving the computer algorithms used to analyze the electrode signals and improving the electrical contacts, the “snake skin” should be ready for a field trial in robotics or prosthetics. Ref.KY32-DS18B20KY45-LM61CIM3XKY45-LM35DT

Two new USB Type-C-certified port-controller ICs have been introduced by STMicroelectronics.  The ICs offer built-in protection which help designers implement interfaces cost-effectively to support their required blend of USB features. These can include power negotiation, managed active cables, and support for guest protocols. USB Type-C specifies reversible plug orientation and cable direction, which simplifies attaching and powering a wide range of devices. The Type-C connection also consolidates support for all USB features including 480Mbps USB 2.0 and 10Gbps USB 3.1 data exchange, power delivery from 5V/0.5A up to 20V/5.0A, managed active cables that extend connection distance, and alternate mode that even allows guest protocols such as HDMI or DisplayPort to use the same cable. Making things simpler for users requires more complex interface electronics to setup each connection correctly. In addition, the 20V maximum bus voltage (VBUS) for power delivery demands extra protection for low-voltage circuitry. ST’s new controller ICs simplify choices for designers, with one device dedicated to controlling downstream-facing ports (DFP), and one that can handle either downstream-facing (DFP), upstream-facing (UFP), or dual-role (DRP) use. Both new ICs support Type-C cable-attachment and connector-orientation detection and can operate over a wide supply range of 3-22V with no external voltage regulator, saving component count and board real-estate. Manufactured using ST’s high-performance analog CMOS process, the new USB Type-C controllers combine low power consumption with robust, high-voltage capability. Over-voltage protection up to 22V for the CC lines and up to 28V for the high-voltage pins is also built-in, which prevents damage in the event of accidental short-circuit to VBUS. There is also on-chip discharge circuitry for the VBUS and VCONN power lines, which allows cables to be disconnected safely. The STUSB4710 DFP controller targets power-source applications such as AC adapters and power supplies, power hubs, docking stations, smart plugs, and displays. The IC integrates all the circuitry needed to negotiate power delivery with connected devices, and can support up to 5 Power Delivery Profiles. Through its embedded Non-Volatile Memory, it is fully customizable and can handle the entire connection setup with no external CPU involvement; hence it can be used directly without any extra software or firmware. In case of multi-port applications (4-port power hub, for instance), an I²C interface allows a parallel connection of multiple STUSB4710 ICs to a microcontroller (MCU) to implement power-sharing algorithms. The STUSB1602 can manage USB Type-C ports in power sources or devices. On-chip Configuration-Channel (CC) control logic manages the entire connection setup including selecting the VBUS default, medium-current, or high-current mode. In addition, the device integrates a protected and programmable 600mA VCONN power switch to support accessories and active cables. The STUSB1602 also implements a USB PD physical layer (including a Bi-phase Mark Coding IP) to support power-delivery software stack implemented by an external MCU. The hardware and the software is USB PD 2.0 certified both as a Sink and a Source. Furthermore, it is compatible with USB PD 3.0 core features and most options. The STUSB1602 supports accessory modes and dead-battery mode. Ref.KY32-CP2200-GQKY32-CP2110-F01-GM  

Diodes Incorporated introduced the BCR401U, BCR402U and BCR405U. Appealing to lighting designers, these constant-current regulators enable simple driving of low- current LED strips and panels in the commercial and industrial lighting sectors. Targeted at 12 V and 24 V linear LED strips, these regulators increase light output efficiency as they only require a 1.4 V supply, allowing more LEDs in the string. By achieving regulation within ±10% and providing preset options of 10 mA (BCR401U), 20 mA (BCR402U), and 50 mA (BCR405U) that can be adjusted up to 100 mA, these regulators simplify the design, minimize component count, and overall enhance system reliability by integrating the driver. Combined with the improved efficiency and longer life offered by LEDs, many lighting applications including advertising, emergency, refrigeration, decorative, architectural and other general forms are being superseded with this emerging light source.  Delivering a regulated current over a wide 1.4 V to 40 V supply, the BCR40xU will tolerates voltage spikes and LED short failures in strings, whilst preserving LED brightness and longevity. This, along with a negative temperature coefficient that reduces the LED current with rising temperature, helps to increase the LED lifespan by reducing dissipation and additionally enables parallel device operation for increased current in applications requiring more than 100 mA. The BCR40xU operates as a linear LED driver, minimizing the likelihood of EMI, which is particularly important in medical lighting and other sensitive applications, while LED brightness can be PWM controlled with <1% duty cycle at 25 kHz allowing accurate dimming to low light levels. The BCR401U, BCR402U and BCR405U LED drivers are offered in the industry-standard SOT-26 (SC74R) package. Ref.KY32-BCR401U E6327KY32-BCR402UKY32-BCR405UE6327  

Texas Instruments (TI) introduced the industry's first differential inductive switch, with a dual-coil architecture that automatically compensates for variations in temperature and component aging. The LDC0851 detects the presence or absence of conductive material by using a simple coil drawn on a printed circuit board (PCB). This unique approach enables low-cost, highly reliable switching implementations for a variety of uses including buttons, knobs, door open/close detection, and speed and directional sensing in personal electronics, appliances, industrial equipment and communications applications. The LDC0851 provides a temperature-stable switching accuracy of better than 1 percent of the sensor coil diameter, removing the need for production calibration and minimizing part-to-part variation. Unlike alternative sensing technologies, the LDC0851's contactless and magnet-free design is immune to dirt, dust or other environmental factors, providing designers a reliable, low-cost solution. The device joins TI's distinctive portfolio of inductive-sensing integrated circuits (ICs) including the LDC1614 family of multichannel inductance-to-digital converters.  Key features and benefits of the LDC0851: ·Stable switching threshold:The differential architecture maintains the switching threshold across variations in temperature, humidity and other environmental factors, as well as providing immunity to component aging for stable, long-term performance. ·High accuracy:The device can deliver better than 1 percent switching accuracy, which is up to 10 times more accurate than magnetic sensor-based designs, reducing the need for production calibration. ·High reliability:The device's immunity to nonconductive contaminants such as oil, dirt and dust can help extend product lifetimes and reduce replacement costs. The solution is also unaffected by direct current (DC) magnetic fields, ensuring robust operation and reliability in a wide range of environments. ·Low power:Duty cycling of the LDC0851 allows for less than 20-µA average current consumption at 10 samples per second, which is up to five times lower than competitive solutions. Tools and support to jump-start design The LDC0851EVM evaluation module helps designers easily configure the LDC0851 and start designing it into a system without programming.（The LDC0851EVM evaluation module.）An incremental rotary encoder reference design (TIDA-00828) demonstrates the LDC0851 in a simple 32-position rotary-knob design. Using only two LDC0851 inductive switches, the system can track rotation position and direction, and designers can easily scale the number of encoder positions up or down.（TIDA-00828 Inductive Sensing 32-Position Encoder Knob ReferenceDesign using the LDC0851.） System designers can start their inductive-sensing design in minutes with TI's WEBENCH Coil Designer. This online tool simplifies sensor-coil design based on application and system requirements. The optimized design is exportable to a variety of computer-aided design (CAD) programs to quickly incorporate the sensor coil into an overall system layout. Ref.KY362-LDC0851EVMKY362-LDC1614EVM     

A simple and efficient PWM lamp dimmer using timer IC NE555 is discussed in this article. Yesterdays linear regulator based dimmers can only attain a maximum efficiency  of 50% and are far inferior when compared to the PWM based dimmers which can hit well over 90% efficiency. Since less amount of power is wasted as heat, the switching elements of PWM dimmers require a smaller heat sink and this saves a lot of size and weight. In simple words, the most outstanding features of the PWM based lamp dimmers are high efficiency and low physical size. The circuit diagram of a 12V PWM lamp dimmer is shown below. As you can see, NE555 timer IC which is wired as an astable multivibrator operating at 2.8KHz forms the heart of this circuit. Resistors R1,R2, POT R3 and capacitor C1 are the timing components. Duty cycle of the IC’s output can be adjusted using the POT R3. higher the duty cycle means higher the lamp brightness and lower the duty cycle means lower the lamp brightness. Diode D1 by-passes the lower half of the POT R3 during the charging cycle of the astable multivibrator. This is done in order to keep the output frequency constant irrespective of the duty cycle. Transistors Q1 and Q2 forms a darlington driver stage for the 12V lamp. Resistor R4 limits the base current of transistor Q1.Understanding the variable duty cycle astable multivibrator.As I have said earlier, the variable duty cycle astable multi vibrator based on NE555 forms the foundation of this circuit and a good knowledge on it is essential for designing projects like this. For the ease of explanation the timing side of the astable multivibrator is redrawn in the figure below.Upper and lower halves of the POT R3 are denoted as Rx and Ry respectively. Consider the output of the astable multivibrator to be high at the starting instant. Now the capacitor C1 charges through the path R1, Rx, and R2. The lower half of POT R3 ie; Ry is out of the scene because the diode D1 by-passes it. When the voltage across the capacitor reaches 2/3 Vcc, the internal upper comparator flips its output which makes the internal flip flop to toggle its output. As a result the output of the astable multivibrator goes low. In simple words, the output of the astable multivibrator remains high until the charge across C1 becomes equal to 2/3 Vcc and here it is according to the equation Ton =0.67(R1+Rx+R2)C1.Since the internal flip flop is set now, the capacitor starts discharging through the path R2,Ry into the discharge pin. When the voltage across the capacitor C1 becomes 1/3 Vcc, the lower comparator flips its output and this in turn makes the internal flip flop to toggle its output again. This makes the output of the astable multivibrator high. To be simple, the output of the astable multivibrator remains low until the voltage across the capacitor C1 becomes 1/3 Vcc and it is according to the equation Toff = 0.67(R2+Ry)C1. Have a look at the internal block diagram of NE555 timer shown below for better understanding.How does the frequency remain constant irrespective of the position of POT3 knob?.What ever may be the position of  POT3 knob, the total resistance across it remains the same (50K here). If anything decreases in the upper side (Rx) the same amount will be increased in the lower (Ry) and the same thing gets applied to the higher(Ton) and lower(Toff) time periods. The derivation shown below will help you to grasp the matter easily.With reference to Fig 2, we have:Ton = 0.67(R1+Rx+R2)C1Toff= 0.67(R2+Ry)C1Total time period of the output waveform “T” is according to the equation :T = Ton + ToffThere fore, T = 0.67(R1+Rx+R2+R2+Ry)C1                        T= 0.67(R1+2R2+Rx+Ry)C1We know that Rx+Ry = R3There fore T = 0.67(R1+2R2+R3)C1Therefore frequency F = 1/(0.67(R1+2R2+R3)C1) From the above equation its is clear that the frequency depends only on the value of the components C1, R1, R2  and the over all value of R3 and it has nothing to do with the position of R3 knob.  Ref:KY32-NE555KY32-NE555.NE555DR.NE555P 

The introduction of the LDD-ES8, a customisable gigabit Ethernet switch module for industrial, commercial and building automation data services, has been announced by LDD Technology. The standard LDD-ES8 module is an 8 port unmanaged Ethernet Switch on a PC/104-Plus form factor intended for use in embedded applications. It features a high performance, low latency, switch able to handle full-rate gigabit packets on all ports simultaneously.Auto-negotiation allows each port to operate at 10/100/1000 Mbits with dual LEDs per port to indicate negotiated speed and link activity. Power is provided from the PC/104 stack or through a Molex Microclasp connector. The LDD-ES8 module is designed for fully independent operation but a USB port is provided to allow monitoring of port performance if required. Power consumption is typically 5W with all ports operating at 1 Gbit/sec.The LDD-ES8 Gigabit Ethernet switch was developed in response to a number of enquiries for custom designed products from customers who had been unable to find suitable off-the-shelf products which met their performance, footprint and end product life requirements.LDD Technology is able to offer an efficient and cost-effective customisation service in the event that customers require a design with a different number of ports or in a different form factor. The module has been designed using programmable FPGA technology which offers end users a further range of customisation options not normally found on competitive products based on dedicated devices with limited programmability.This allows customers the option of including the functionality of the standard Ethernet Switch into other designs which may require Ethernet switching as part of a more complex system with additional interfaces or processing being included in the FPGA as required.“Our LDD-ES8 Gigabit Ethernet Switch is an excellent example of how our extensive custom design experience for many different clients can be used to create a flexible standard solution for many applications” commented Malcolm Locke, Managing Director of LDD Technology. Ref:KY32-EP1S60B956C6KY32-XC7K325T-2FFG900CKY32-EPF8636ALC84-3