Build a $1 per Watt parallelizable MPPT controller

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Jonathan Bruneau designed a $1/W maximum power point tracker used to extract maximum power from solar panels and published his project on hackaday.io:

Maximum Power Point Tracking (MPPT) is a technique whereupon special electronics attempts to extract the optimal amount of energy from a solar panel. This optimal point fluctuates in function of a variety of factors including: temperature, quantity of incoming light, solar panel age, etc.

Current MPPT controllers tend to be expensive. They range from tens of dollars for 3W supplies to hundreds of dollars for 100W and above. Lower costs can be achieved but typically trade-off functionality essential for proper MPPT operation. This makes MPPTs poor candidates for cost sensitive applications

If the cost could be reduced to a more attractive price point, MPPT controllers could become synonymous with solar panels, opening doors for new renewable applications.

Build a $1 per Watt parallelizable MPPT controller – [Link]

Silicon-air Battery A New Achievement in Energy Storage Area

Researchers from Jülich Research Center (Jülich, Germany) announced their new invention, a silicon-air battery. The new battery features high energy density so it’s a lighter and smaller battery solution.

silicon-air-battery

Silicon-air battery is made of silicon which means it’s cheap to make from virtually unlimited resources rather than a rare earth material. It can deliver energy for up to 46 days (about 1000 hour). It’s a big step but it not means it’s the perfect solution. This new type of battery suffers from short lifetime of just a few minutes, therefore the researchers made a workaround by refills the electrolyte from time to time using a pump system.

About how it works, the news states that “As long as the silicon anode is in contact with the electrolytes, the battery will generate electricity. With this method, the Jülich battery remained active until the silicon was used up after more than 1100 hours. Once the electrode is used up, it can be reactivated by replacing the anode.”

Via: elektormagazine

Bq501210 the Wireless Power Transmitter from TI

Texas Instruments (TI) announced the Qi-Certified Wireless Power (WPC) v1.2 solution for 15-W operation wireless power transmission for Smart Phones, Tablets, and Other Handheld devices, Point-of-Sale devices and other custom wireless power applications.

Bq501210 supports Bi-directional Communication and fast charge operation with compatible receivers. The user is informed for the state of charge by 10 configurable LED codes that indicate also fault status.

If you’re not familiar with the term of wireless power transmission then let’s see how TI describes it in the datasheet. It basically consists of a transmitter and receiver coils. When the receiver coil is positioned on the transmitter coil with some distance (wireless), magnetic coupling occurs when the transmitter coil is driven. The flux is coupled into the secondary coil, which induces a voltage and current flows. The secondary voltage is rectified, and power can be transferred effectively to a load.

According to the datasheet, bq501210 supports multiple levels of protection against heating metal objects placed in the magnetic field.

bq501210_BD

TI provides an evaluation module bq501210EVM-756 costs 150$ with the following features:

  • WPC v1.2 15-W charging capability with bq55221 receiver.
  • 5-W solution for WPC v1.1 receivers.
  • 15-V to 19-V input and fixed operatiing frequency for full 15-W results.
  • 12-V input for reduced power (> 10W) solutions.
  • Enchanced Foreign Object Detection (FOD) with FOD ping detecting objects prior to power transfer.
  • WPC v1.2 FOD, WPC v1.1 FOD and WPC v1.0 Parasitic metal Object Detection (PMOD).
  • Transmitter-coil mounting pad providing the corect ereceiver interface.
  • Compact power section design using the bq500100 NexFET power stage.
  • Wurth 760 308 141 transmitter coil with no magnet.
  • LED and audio indication of power transfer.

bq501210evm-756

Bq501210 is available in 9*9mm 64-VQFN package and is priced at US$3.75 in 1,000-unit quantities.

Via: eeweb

ClearFog Base from SolidRun A New 90$ Single Board Computer

SoildRun launched ClearFog Base, a SBC (Single Board Computer) designed for IoT and networking applications.

ClearFog Base includes SoM (System on Module) designed by SolidRun too and it is based on Marvell’s ARMADA A388 SoC (System On Chip) with Dual core ARM Cortex A9 @ up to 1.6 GHZ and supports Linux Kernel 3.x and OpenWrt OS.

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The Board features up to 2GB storage and optional 8GB uSD/4GB eMMC with the following connectivity options, 1× mPCIE, 1×USB 3.0 port, 2 ×Port dedicated Ethernet  and 1×SFP.

ClearFog_TOPClearFog_Down

ClearFog Base has a mikroBUS™ connector to add accessories and supports MikroElektronika’s Click board modules. More than 150 Click boards are available, including I/O, wireless, sensors, transceivers, displays, encoders, pushbuttons, and advanced GPS modules.

ClearFogFeatures

The price of ClearFog base can reach 117$ with the optional power adapter, 8GB SD card and 4GB eMMC.

Via: cnx-software

Thermal-imaging DMM, in distribution

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Distributor Conrad Business Supplies has the thermal multimeter 279 FC from Fluke, that combines a thermal imager with a fully-featured true RMS digital multimeter to enable faster and more thorough troubleshooting with a single tool. By Graham Prophet@ edn-europe.com

The 279 FC’s thermal multimeter measures AC/DC voltage, resistance, continuity, capacitance, diode test, min/max, and can carry out frequency tests. At the same time, the integrated thermal imager allows the 279 FC to quickly and safely check for hot spots in fuses, wires, insulators, connectors, splices, and switches and then troubleshoot and analyze issues with the DMM. An integrated 3.5 inch (8.89 cm) full-colour LCD screen provides clear viewing of data and images. This powerful combination ensures electricians and technicians can carry fewer tools and have a greater chance of identifying an issue wherever it might occur.

Thermal-imaging DMM, in distribution – [Link]

CP2102N – The Latest USB Controller From Silicon Labs

CP2102N-press

Recently, Silicon Labs announced a new USB controller called CP2102N which is part of the USBXpress™ bridge devices family.
CP2102N have a battery charger detect functionality to notify an external battery charger with the amount of current available from the USB interface (100 mA, 500 mA or 1.5A). CP2102N also have up to 7 GPIOs that can be controlled from the host, and a RS485 pin which is an optional control pin that can be connected to the DE and RE inputs of the transceiver to be asserted during UART data transmission.

The key features according to the datasheet:

  • Integrated USB transceiver; no external resistors required.
  • Integrated clock; no external crystal required.
  • Internal 960-byte programmable ROM for vendor ID, product ID, serial number, power descriptor, release number, and product description strings.
  • On-chip voltage regulator — 3.3 V output.
  • USB 2.0 full-speed compatible Data transfer rates up to 3 Mbaud USB.
  • Battery Charger Detection (USB BCS 1.2 Specification).
  • Remote wakeup for waking a suspended host.
  • Low operating current : 9.5 mA.
  • Royalty-free Virtual COM port drivers.

The new chip is available in the following packages QFN20, QFN24, or QFN28.

The price per unit is $0.91 (USD) in 10,000-unit quantities according to the press release, and an evaluation kit for CP2102N-EK is available at $25.00.

Via: circuitcellar

IRis – An Infrared Sensor using Photodiode amplification Circuit

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[devttys0] designed a sensitive IR detector for capturing weak infrared signals. He shared in detail how he designed the circuit, beginning from the basic components, walking through solving the problems and finally ended up with a complete working circuit.

Craig Heffner/[devttys0] built this circuit for a friend’s Defcon talk, Blinded by the Light, the talk concerned about the emitted IR signals from the IR proximity detector in our devices like mobiles, and how we can identify the type of the device/OS using these signals.

Craig wanted to build a general purpose IR detector to capture and analysis the raw IR transmissions where IR receivers is designed to sense the modulated IR signals at 36-38 kHz. “But there is so much more to the world of IR than this” Craig said.

The first basic idea in the design is to use transimpedance amplifier which is basically a current-to-voltage converter.
When photons strike the photo diode, it will actually emit charge carriers, so the output of this sensor is a current. The output voltage (Vout= Ip*Rf) is linear in respect to the current.

IRis_cir1

The major problem with this particular configuration is the unwanted high frequency oscillation, so a capacitor was added in parallel with the feedback resistor.

IRis_cir2

The next problem solved by Craig, is the saturation of the amplifier in high and low side by adding some bias resistors just to keep the reference voltage of the positive input of the op-amp at just under 200 millivolts.

To prevent saturation in high side he added three diodes, in fact three JFETs configured as diode, in the feedback path. The reason of using JFET configured as a diode is that it has less leakage current than normal silicon diodes, so when the voltage exceeds 3*0.7=2.1V then they short the feedback resistor, this point is important in our design because it has a current flow from photo diode.

The last thing to solve in first stage of the design is the problem of constant current from ambient light, which will generate a DC component in the output. So Craig added a high pass filter in the output.

IRis_cir3

Now the circuit will still have some analog signals in output, noise and some negative spikes. So he cleaned things up by using a comparator with a Schottky diode in the non-inverting input to omit the negative pulses less than 0.2 Volt.

IRis_cir4

To see the full details of the design you can see the video below, and also you can reach the design files (SCH & PCB) over Github.

In addition, you can see the references pointed by Craig in his site analogzoo.

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HT48R002 A Very Cheap OTP MCU as Low as $0.085/Unit

A highlight from CNXSoft about Holtek HT48R002 MCU as the cheapest MCU.
HT48R002 is a 8-Bit OTP (One Time Programming) MCU with the following key features (datasheet):

  • 8-bit RISC MCU @ 8MHz.
  • 1K x 14-bit ROM (OTP).
  • 64 x 8-bit RAM data memory.
  • 6x I/O including 1x external interrupt pin, and 1x 8-bit timer.
  • Two oscillators –  Internal high speed RC: HIRC; Internal low speed RC: LIRC.
  • Fully integrated internal 8MHz oscillator requires no external components.
  • Low voltage reset function Operating Voltage – 2.3 to 5.5V.
  • Package types: 8-pin DIP/SOP, 10-pin MSOP and 16-pin DIP/NSOP

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As we mentioned, this MCU has OTP ROM which means that you can program it with your code just one time. If your end product will not have any update in the firmware, then OTP MCUs will be a good choice for you.

If you’re still searching for another cheap MCU, not OTP one, that costs $0.32 per unit for 1k orders, it’s PIC10F200 from MICROCHIP a 8-bit MCU with 256B flash and 16B RAM, available in either SOT-23 or 2×3 DFN packaging.

Via: cnx-software

DIY ECG with 1 op-amp

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A DIY ECG made from single op-amp (LM741) and 5 resistors by Scott Harden:

I made surprisingly good ECG from a single op-amp and 5 resistors! An ECG (electrocardiograph, sometimes called EKG) is a graph of the electrical potential your heart produces as it beats. Seven years ago I posted DIY ECG Machine on the Cheap which showed a discernible ECG I obtained using an op-amp, two resistors, and a capacitor outputting to a PC sound card’s microphone input.

DIY ECG with 1 op-amp – [Link]