Tag Archives: Power

Power ON Delay Switch


Power-ON Delay Switch which can be used in all applications requiring a delay during power-on from 1 to 60 seconds.


  • Supply input 5 VDC
  • Relay output SPDT relay
  • Relay specification 5 A @ 250 VAC
  • Preset adjustable range function
  • Power-On LED indicator
  • Screw terminal connector for easy relay output connection
  • Four mounting holes of 3.2 mm each
  • PCB dimensions 44 mm x 42 mm

Power ON Delay Switch – [Link]

Nixie Tube Energy Meter


John Whittington decided to build a Nixie tube energy meter to measure his house power consumption.

 An Arduino would be the microcontroller but I wanted the meter to provide some form of data stream for a web based energy history. To make it an IoT, I a paired ESP8266 with it. I used both together because the Arduino ADC has a better resolution and has been tried and tested.

Nixie Tube Energy Meter – [Link]


Adding a USB power port to a switch for IoT


Jesus Echavarria @ jechavarria.com has tipped us with his latest project. In this project he adds a USB power port to a switch.

Also I need a power supply for the Arduino board, and I think that, better than a external USB AC wall adaptor or power supply, is modify the switch to add it a USB power port that can power the Arduino board. I’ve got at home a TP-Link TL-SF1008D, a simple 8 port 10/100 Mbps switch. So, let’s go to open it and add it the USB port!

Adding a USB power port to a switch for IoT – [Link]

Power Management of Xilinx ZedBoard using MMPF0100

This reference design is a power management of Xilinx ZedBoard using MMPF0100 Power Management Integrated Circuit (PMIC). A PMIC is an IC for managing power requirements of the host system and is commonly used in a system-on-chip (SoC) device. On the other hand, the Xilinx ZedBoard, a development board based on Zync-7000 AP SoC, provides appropriate hardware capabilities for interfacing with a number of peripherals and compatible expansion headers for Xilinx Analog to Digital Converter (XADC), FPGA Mezzanine Card (FMC) and Digilent Pmod.

This design utilizes the Freescale’s MMPF0100 PMIC. The 12V from a barrel-jack connector, which supplies the Zedboard, must be stepped down to 3.6V in order to meet the input supply requirement of the MMPF0100. The MMPF0100 provides a highly programmable/ configurable architecture, with fully integrated power devices and minimal external components. The buck regulators in the PF0100 may be configured as five independent regulators to power VCCINT, VCCAUX, VCCO2, VCCO_DDR and VTT_DDR rails. This allows the VTT_DDR rail to automatically track half of VCCO_DDR if they are connected to SW4 and SW3A respectively. The boost regulator in the PF0100 is utilized to supply the VCC5V0 rail. The VCCO1 rail requires a buck converter to convert the available 3.6V to 3.3V, while being capable of supplying 3A. Because most peripherals are supplied through this rail, the current being drawn may vary. Therefore, to ensure safe operation, both this rail and the VCCINT rail are provided with sufficient margins. The Freescale Switched-mode Power Supply (SMPS) MC34713 provides a good option for achieving this. The MC34713 is a highly integrated, space efficient, low cost, single synchronous buck switching regulator with integrated N-channel power MOSFETs.

PMICs minimize energy loss, and hence, they are useful in mobile devices, televisions, and cars. With up to six buck converters, six linear regulators, RTC supply, and coin-cell charger, the MMPF0100 can provide power for a complete system, including applications processors, memory, and system peripherals, in a wide range of applications.

Power Management of Xilinx ZedBoard using MMPF0100 – [Link]

5V & 12V Regulated Power Supply


This project can be used to power up TTL and CMOS based projects, it provides 5 VDC & 12 VDC outputs with an onboard mains transformer.  The project is based on the industry popular 7800 series voltage regulator in TO220 packages.


  • Input: 240 VAC
  • Output: 5 V, 12 V @ 600 mA regulated low ripple DC voltage
  • Thermal overload/short circuit protection (provided by IC feature)
  • Power Battery Terminal (PBT) for easy input and output connection
  • External On/Off switch connection possible
  • LED indication for outputs
  • Four mounting holes of 3.2 mm each
  • PCB dimensions 87 mm x 49 mm

5V & 12V Regulated Power Supply – [Link]

Teardown & Repair of a Stanford Research PS350 5000V, 25W High Voltage Power Supply

In this episode Shahriar repairs a Stanford Research Systems Model PS350 5000V-25W High Voltage Power Supply. The unit continuously displays 2.5kV without the output being enabled and produces no output voltage. Verification of power supply voltages reveals the issue is linked to a disconnected 15V voltage regulator IC. After the repair, the output voltage is verified with both positive and negative outputs. The principle operation of the instrument as well as the Cockroft-Walton high voltage generator is reviewed.

Teardown & Repair of a Stanford Research PS350 5000V, 25W High Voltage Power Supply – [Link]

Hardware Protection – OverVoltage and OverCurrent


Maurizio @ dev.emcelettronica.com discuss about the different aspects of protecting power supplies from overvoltage and overcurrent.

Power processing is one of the most important aspects on electronic design. The power is unique for a typical system because it gives the system life. Before starting to make the project for a power supply we need to analyze some aspects: Which kind of radio/electromagnetic interference is the device going to face ? What about maintenance requirements? And finally which environment conditions (temperature, humidity, vibrations) will the device be exposed to?

Hardware Protection – OverVoltage and OverCurrent – [Link]

Laser Diode Driver


Laser Diode Driver project will help you safely drive (constant current) a 3 mW visible Laser Diode for your application.

  • Input supply – 2.5 to 6 VDC
  • Onboard preset to adjust the current flow to the Laser Diode
  • Power-On LED indicator
  • Header connector for easy input supply and LASER DIODE module connection
  • Laser diode is not included
  • Circuit is designed around Sanyo DL3148-025 LASER DIODE
  • PCB dimensions 37 mm x 42 mm

Laser Diode Driver – [Link]

Triacs – How to calculate power and predict Tjmax


An application note from NXP on how to calculate the power dissipated by the triac:

This Application Note describes how to calculate the power dissipation for triacs and Silicon Controlled Rectifiers. Thermal calculations are also included to help the circuit designer to predict the maximum junction temperature or calculate the required heatsink thermal resistance. Four worked examples ensure that all the power and thermal questions that arise during the design process are covered.

Triacs – How to calculate power and predict Tjmax – [Link]

Get a constant +5V output by switching between a +5V input and a single-cell LI+ rechargeable cell


App note from Maxim Integrated on providing smooth power from two sources. Link here (PDF)

Design provides a simple method for maintaining an uninterrupted +5V even while switching between the external +5V supply and a rechargeable single-cell Li+ battery.

Get a constant +5V output by switching between a +5V input and a single-cell LI+ rechargeable cell – [Link]