Charging batteries rapidly and safely


by Steve Taranovich @

Any hobbyist can charge a battery quickly, but can you do it without an explosion, excessive heating or major degradation in battery cycle life?

Well many companies have managed fast charging techniques that typically use specialized algorithms. These algorithms take into account the chemistry of the battery and some sort of non-standard charging rate curve. Many device manufacturers and wireless operators are now providing a minimum two-year warranty on smart phone devices setting 800 cycles as the battery cycle life of the battery.

Charging batteries rapidly and safely – [Link]

Emon-server – 555 Timer as power usage sensor


by dkroeske @

A cheap 555 timer chip acting as Schmitt trigger combined with a phototransistor or LDR is taped to the ‘flashing light’ or ‘pulsing magnet’ on the electricity meter. The output of the 555 timer chip is connected to one of the GPIO pins on the Raspberry Pi. A Python script (executing in the background) recording 555 events is calculating actual energy usage [e.g. Watt] every time the 555 is signaling and stores epochs in an SQLite3 database. From this, another Python script (executed from e.g. cron) generates all kinds of energy usage information (e.g. kWh or kWday or whatever). Using Node.js (running on the same Pi) all data is ‘RESTified’ enabling spreading out to the W3. To maintain privacy JSON web tokens are required every time the service is queried. Oh, and there is also a Pimatic plugin available (here)

Emon-server – 555 Timer as power usage sensor – [Link]

With HAMMOND 1553W enclosures the rain won’t surprise you


Favourite series 1553 hand-held enclosures are now available even in a water-resistant version with IP65 rating.

Ergonomic enclosures of the 1553 series with a non-slipping surface found their place on a market very quickly. Precise construction with brass bushings, stainless steel screws included, easy PCB placing on standoffs and other details make this series of enclosures universal for practically any “mobile” applications.

Despite very well fitting parts of an enclosure minimizing a possibility of a dust ingress into enclosure, there certainly are applications with a higher risk of water and dust penetration. For these cases the new “W” version is suitable, i.e. 1553W with integrated sealing and a whole construction designed so as to meet IP65 requirements. Fixing positions for screws are located outside the gasket ensuring sealing integrity.

Hammond 1553W series is available in “B”, “C” and “D” sizes, i.e. 1553WB (117x79x25mm), 1553WC (117x79x32mm) and 1553WD (147x90x25mm). All sizes are further available in two colours – whit-grey and black (GY/BK). Further details can be found in datasheets at particular types below this article.

With HAMMOND 1553W enclosures the rain won’t surprise you – [Link]

Single-cell 5-A Li-Ion battery charger with MaxCharge™ technology



TI’s new bq25890, bq25892, and bq25895 5A chargers with TI’s MaxCharge™ technology charge your mobile device faster while keeping your device cooler. The switch-mode chargers can charge a 1-S Li-Ion cell to 80% capacity in 30 minutes, while traditional devices only reach 30%. The I2C-controlled chargers’ high efficiency and thermal management result in the fastest, safest and coolest charging capability.

Key features and benefits

  • Fast charging to high capacity battery with up to 5A high charging current
  • Optimized for high voltage input: >91% charging efficiency at 3A with 9V input
  • Innovative Input Current Optimizer (ICO) to maximize input power without overloading adapter
  • Resistance compensation from charger output to cell terminal to enhance power delivery to battery
  • Integrated ADC for charging system monitoring

Single-cell 5-A Li-Ion battery charger with MaxCharge™ technology – [Link]

Technology breakthrough claimed by flexible electronics specialist


Flexible electronics specialist FlexEnable says it has made a technology breakthrough which makes the manufacture of glass free LCDs practical and cost effective. Supporting the development, the company will demonstrate a full colour conformal in plane switching organic LCD at the forthcoming SID event in San Jose. It adds the display is light, thin and robust.

Flexible electronics specialist FlexEnable says it has made a technology breakthrough which makes the manufacture of glass free LCDs practical and cost effective. Supporting the development, the company will demonstrate a full colour conformal in plane switching organic LCD at the forthcoming SID event in San Jose. It adds the display is light, thin and robust.

Technology breakthrough claimed by flexible electronics specialist – [Link]

Buck controller allows 48V to 1V direct step-down

Intersil 8117

by Richard Quinnell @

Aiming to simplify design and increase power density in industrial systems, Intersil has developed the ISL8817 synchronous buck controller. The device accepts DC input voltages from 4.5V to 60 V and produces a selectable output voltage between 0.6V and 54V at up to 20A output current. Able to operate over a wide switching frequency (100 kHz to 2 MHz) with a low duty cycle (40 nsec minimum on time), the controller is able to step down from a 48V source to a 1V output in a single stage. This allows industrial applications using a 48V power distribution bus to provide the many voltages that modern CPUs and FPGAs require without the need for an intermediate low-voltage stage. This both increases power density in such systems as well as reducing conversion losses.

Buck controller allows 48V to 1V direct step-down – [Link]

LDO regulator squeezes into wearables

Semtech SC563by Susan Nordyk @

Housed in a tiny 1.6×1.2-mm, 0.6-mm thin package suitable for wearable electronics and other space-constrained battery-operated applications, the SC563 low-dropout regulator from Semtech provides two regulated outputs at up to 300 mA each, while its fixed output voltages eliminate the need for external resistor divider networks. The device’s ultra-small footprint and low dropout voltage of 180 mV enable designers to implement power supplies where small size and high efficiency are paramount.

The SC563 accepts an input supply voltage of 2.3 V to 5.5 V. It has separate input, output, and enable pins for each LDO channel. Using the lowest possible input voltage for each output voltage reduces the power loss for each rail. Quiescent current of just 50 µA for each channel helps extend battery life. The regulator also offers short-circuit, undervoltage lockout, and thermal protection to prevent device failures.

LDO regulator squeezes into wearables – [Link]

Intelligent Motion-Sensing Platform

The MMA955xL platform as a sensor hub is an intelligent sensing hub with built-in accelerometer, signal conditioning, and data conversion with 32-bit programmable microcontroller and temperature sensor. In addition, it has a second I2C bus and one external analog input, which can be monitored using the on-chip Analog-to-Digital (ADC). This unique blend transforms Freescale’s MMA955xL into an intelligent, high precision, motion-sensing platform able to manage multiple sensor inputs.

The combination of low power consumption and powerful features means that the MMA955xL platform can effectively operate as a power controller for handheld units such as industrial scanners, Personal Digital Assistant (PDA), and games. The host platform can put itself to sleep with confidence that the MMA955xL device will issue a wake request should any external event require its attention. The MMA955xL device is programmed and configured with the codewarrior development studio for micro-controllers software. This standard integrated design environment enables customers to quickly implement custom algorithms and features to exactly match their application needs. Using the master I2C port, the MMA955xL device can manage secondary sensors, such as pressure sensors, magnetometers, or gyroscopes. This allows sensor initialization, calibration, data compensation, and computation functions to be off-loaded from the system application processor. The MMA955xL device also acts as an intelligent sensing hub and a highly configurable decision engine. Total system power consumption is significantly reduced because the application processor stays powered down until absolutely needed.

This device is optimized for use in portable and mobile consumer products that can make system-level decisions required for practical applications such as gesture recognition, pedometer functionality, tilt compensation and calibration, and activity monitoring. This may be applicable to tablets, digital cameras, smartbooks, laptops, gaming and security system as well as used in medical applications.

Intelligent Motion-Sensing Platform – [Link]

Pozyx shield gives position



Resolving the position of free roaming robots can be quite challenging. You can only expect to get accuracy of around 6 to 10 meters by using a standard low-cost GPS system and that can be further downgraded by poor signal strength inside buildings. Bluetooth and WiFi positioning can achieve 1 to 5 metres resolution but that’s often not enough. The Pozyx system has been developed to achieve a positional accuracy of 10 cm and works indoors or outdoors.

Four ‘Anchor’ transceiver units attach to walls or fences surrounding the space in which the Pozyx Shield operates. Communication between the shield and the four anchors allows the shield to determine its position and orientation within its operational area.

Pozyx shield gives position – [Link]

Smart Medicine Box


by Mingyuan Huang & Jie Zhang:

Our ECE 4760 final project is to build a microcontroller based smart medicine box. Our medicine box is targeted on users who regularly take drugs or vitamin supplements, or nurses who take care of the older or patients. Our medicine box is programmable that allows nurses or users to specify the pill quantity and day to take pills, and the serve times for each day. Our smart medicine box contains seven separate sub-boxes. Therefore, nurses or users can set information for seven different pills. When the pill quantity and time have been set, the medicine box will remind users or patients to take pills using sound and light. The specific number of pills needs to be taken will be displayed by a seven segment led display placed on the corresponding sub-box. Compared with the traditional pill box that requires users or nurses to load the box every day or every week. Our smart medicine box would significantly release nurses or users’ burden on frequently preloading pills for patients or users.

Smart Medicine Box – [Link]