Tag Archives: Switch
Graham Prophet @ eedesignnewseurope.com discuss about Melexis magnetic latch and switch sensors. He writes:
Melexis (Tessenderlo, Belgium) has introduced a range of new magnetic latch and switch sensors that feature two silicon dice in the same package, yielding highly reliable devices, which are aimed at automotive applications including transmission, power steering, braking and locks/latches.
Dual die, Hall effect, latch and switch sensor is accurate & redundant – [Link]
Controlling your AC loads using wireless power switch is not a new concept. Several commercial products from several vendors can be found on the market such as Xiaomi’s Mi Smart Socket Plug, SAMSUNG’s SmartThings Power Outlet and Sonoff Pow WiFi Switch from ITEAD.
Using ESP8266 makes the building of a customized WiFi power switch more affordable especially if you start with Sonoff Pow WiFi Switch design and you use a special Arduino C firmware called ESPurna developed by Xose (tinkerman) which is an open source firmware for ESP8266 based wireless switches such as Sonoff POW and many others.
After Xose has built the software ــ ESPurna, he decided to build his own smart switch board to meet his special needs. ESPurna-H electronic design is very similar to Sonoff POW’s one; it uses ESP12 module as a controller and as WiFi transceiver.
AC power monitoring is done using HLW8012 IC which is also present in Sonoff POW. This IC monitors both voltage and current of the AC power, and output RMS voltage, current and active power encoded as a 50% duty cycle square wave where the frequency is proportional to the magnitude. I should mention that ESPurna supports interfacing with HLW8012. In addition AC load is enabled/disabled by using a 10A relay.
ESPurna-H uses HLK-PM01 AC-DC step-down power supply module. The 100-240 VAC input range so the board can be used anywhere in the world and the good performance made Xeos select this module.
Xose designed the board with Eagle CAD and released the schematics, PCB layout and other hardware design files on Github.
by Eric Bogers @ elektormagazine.com:
Nanotechnology repeatedly breaks new records in the area of miniaturization. However, there are physical limits when reducing the size of electronic components and these will be reached in the near future. This means that new materials and components will be required – and it is here where molecular electronics will play a role. Researchers from the Karlsruher Institut für Technologie (KIT) have succeeded in developing a molecular toggle switch, which will not only remain in the selected position, but can also be switched as often as desired without any deformation taking place.
Reliable molecular switch – [Link]
The pressure sensor amplifier built using LM358 op-amp and MPXM2051GS pressure sensor from NXP semiconductor. The circuit provides 4V output for full scale pressure input 0-7.5PSI. One op-amp is used as amplifier and 2nd op-amp is used as comparator to provide an output at set value that can be used as over pressure switch to control a pump or solenoid. This is a low cost general-purpose circuit for those applications where +/-3% performance is acceptable. Multi turn potentiometers are provided for Offset, span adjust & over/under Pressure set point to control output devices like solid state relay, Pump, and solenoid.
- Supply 12V DC
- Pressure Sensor range 0-7.5PSI
- Output 0-4V (Approx.)
- PR1 Multi-Turn Potentiometer Offset
- PR2 Multi-Turn Potentiometer Span Set
- PR3 Multi-Turn Potentiometer Comparator (Switch) output Set
- D1 Power LED
- CN1 4 Header Connector Outputs & Supply Input
Simple Pressure Sensor Amplifier & Over Pressure Switch – [Link]
by Graham Prophet @ edn-europe.com:
Silego Technology has developed a series of integrated power switches for use in mobile and battery powered products, to carry out power gating of functional blocks within a design; the devices come in sub-mm-size chip scale packages, handle currents from 1 to 4 A, and integrate functions such as in-rush current limiting and over-current or thermal protection.
Wafer-scale-packaged integrated FET switches handle 1 – 4A – [Link]
The LTM9100 μModule is an all-in-one solution for controlling, protecting, and monitoring high voltage power supplies up to 1000VDC. A 5kVRMS galvanic isolation barrier separates the digital interface from the switch controller, driving an external N-channel MOSFET or IGBT switch. Isolated digital measurements of load current, bus voltage, and temperature are accessed via the I2C/SMBus interface, enabling power and energy monitoring of the high voltage bus. The LTM9100 saves design time, certification effort, and board area by wrapping all the needed functionality, including digital telemetry and isolated power, in a compact BGA package.
LTM9100 – Anyside™ High Voltage Isolated Switch Controller with I²C – [Link]
The A1230 is a dual-channel, bipolar switch with two Hall-effect sensing elements, each providing a separate digital output for speed and direction signal processing capability. The Hall elements are photo lithographically aligned to better than 1 µm. maintaining accurate mechanical location between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A1230 is a highly sensitive, temperature stable magnetic sensing device ideal for use in ring magnet based, speed and direction systems located in harsh automotive and industrial environments.
The A1230 monolithic integrated circuit (IC) contains two independent Hall-effect bipolar switches located 1 mm apart. The digital outputs are out of phase so that the outputs are in quadrature when interfaced with the proper ring magnet design. This allows easy processing of speed and direction signals. Extremely low-drift amplifiers guarantee symmetry between the switches to maintain signal quadrature. The Allegro patented, high-frequency chopper-stabilization technique cancels offsets in each channel providing stable operation over the full specified temperature and voltage ranges.
Dual-Channel Quadrature Hall-Effect Bipolar Switch Module for Magnetic Encoder – [Link]
Anthony Smith has designed a simple load switch using two transistors and some resistors.
The simple current-limiting load switch shown in Figure 1 will be familiar to most readers. In this circuit, a high level signal applied to the input switches on MOSFET Q2, which energizes the load. The load current is limited by negative feedback applied via Q1.
Load switch with self-resetting circuit breaker – [Link]
Coping with rapid technological advances and finding efficient energy solutions are the keys for development of power electronics of the future. A new research had been done in North Carolina State University about increasing the efficiency of high-power switches.
Silicon Carbide is a compound of silicon and carbon with chemical formula SiC. It is a wide bandgap (WBG) semiconductor, that allows devices to operate at much higher voltages, frequencies and temperatures than conventional semiconductor materials.
Researchers came up with a high voltage and high frequency silicon carbide (SiC) power switch that could cost much less than similarly rated SiC power switches. This research may guide to new applications in power converters like medium voltage drives, solid state transformers and high voltage transmissions and circuit breakers.
Semiconductor devices like the 15kV SiC MOSFET can lead to great potential applications in high voltage and high frequency power converters. However, these devices are not commercially available and their high cost displaces them from industry competition with other alternatives like the standard IGBT (Insulated-gate Bipolar Transistors) that are widely used, but in the same time they dissipate a lot of energy while switching on and off.
The new SiC power switch, called FREEDM Super-Cascode Switch, contains a series of 1.2kV SiC power devices to produce a 15 kV and 40 mA output that can transcend the 15 kV SiC MOSFET in ease of adoption and cost – since it costs only one third of the estimated high voltage SiC MOSFETs. In addition, this new switch is capable of operating in a wide range of temperatures and frequencies due to its proficiency in heat dissipation, which is considered an advantage in power devices.
Since there is no high voltage SiC device commercially available at voltage higher than 1.7 kV, as Alex Huang said – Progress Energy Distinguished Professor, he assures that this solution paves the way for power switches to be developed in large quantities with breakdown voltages from 2.4 kV to 15 kV.
The research took place in North Carolina State’s FREEDM Systems Center which is funded by National Science Foundation. This center’s mission is to modernize the electric grid and mold the generation of leaders by providing all the needed software and hardware tools, funds, and partnerships with Industries. This project had also participated in IEEE Energy Conversion Conference & Expo on September 2016 and it was presented by Xiaoqing Song, a Ph.D. candidate at the FREEDM Systems Center under Huang’s supervision.