Tag Archives: Power

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]

Non-Invasive Smart Electricity Meter


A simple Non-Invasive Smart Electricity Meter using Spark Core. By Yonas Leguesse @ hackster.io:

A non invasive current sensor is connected to the spark core (with a few components), and clamped around a cable in the Mains distribution unit. No wiring is required, however Do not try this at home, as the Mains Distribution Unit should not be tampered with unless one is Licensed to do so.

The back end is Web Application hosted on a LAMP (Linux Apache MySql PHP) setup. Initially it was hosted on a raspberry pi on a LAN, but then I decided to host it on a hosted server. Both instances worked well, its just a matter of preference.

The spark core simply takes periodic readings and sends them to the server, where all of the calculations and filtering is done.

Non-Invasive Smart Electricity Meter – [Link]

Emon-server – 555 Timer as power usage sensor


by dkroeske @ github.com:

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]

AC Power Theory – Arduino maths


by openenergymonitor.org:

AC Voltage and current continually alternate, as the name suggests, if we draw a picture of the voltage and current waveform over time, it will look something like the image below (depending on what’s using power – the current waveform – blue in the diagram below – is what you get if you look at a typical laptop power supply. There’s an incandescent light bulb in there as well).

The image was made by sampling the mains voltage and current at high frequency, which is exactly what we do on the emontx or Arduino. We make between 50 and a 100 measurements every 20 milliseconds. (100 if sampling only current, and 50, if sampling voltage and current – we’re limited by the Arduino analog read command and calculation speed).

AC Power Theory – Arduino maths – [Link]

Researchers Claim 44x Power Cuts


by R. Colin Johnson @ eetimes.com:

PORTLAND, Ore.– Researchers sponsored by the Semiconductor Research Corp. (SRC, Research Triangle Park, N.C.) claim they have extended Moore’s Law by finding a way to cut serial link power by as much as 80 percent. The innovation at the University of Illinois (Urbana) is a new on/off transceiver to be used on chips, between chips, between boards and between servers at data centers.

The team estimates the technique can reduce power up to whopping 44 times for communications, extending Moore’s Law by increasing computational capacity without increasing power. “While this technique isn’t designed to push processors to go faster, it does, in the context of a datacenter, allow for power saved in the link budget to be used elsewhere,” David Yeh, SRC director of Integrated Circuits and Systems Sciences told EETimes.

Researchers Claim 44x Power Cuts – [Link]