300V AC/DC variable power supply

DSC_0012A

300V AC/DC variable power supply project by Dilshan Jayakody

This 300V AC/DC variable PSU is designed for our vacuum-tube, MOSFET and some IGBT related experiments. This PSU consist with 0-300V Variac (variable auto-transformer), 700VA isolation transformer, which is described in previous blog post and high voltage AC-DC converter. Because of the size and weight of these equipment’s we build this PSU as three separate units.
This PSU is capable to supply 20V – 300V 2.3A (max.) output in either AC or DC form. This PSU use high voltage, similar to the ones from ActionPower, and because of that, all the proper construction and precautions are necessary to take. Improper wiring or construction may leads to lethal electrical shock and/or fire. If you are not familiar with high-voltage practices do not attempt this project at home.

aspspi – USBasp SPI terminal

aspspi-write

Nerd Ralph writes:

While writing the picoboot module for avrdude, I noticed avrdude has a terminal mode which allows for commands to be sent to an AVR. The serial programming interface for AVR MCUs uses SPI, similar to the nrf modules. I realized instead of an AVR, the programmer could be attached to any device that communicates via SPI. A couple hours later I had finished writing aspspi for avrdude – which permits a USBasp to be used for interactive SPI communication.

Tutorial: power line communications

Andrianakis Haris produced this detailed article while completing a thesis toward a B.Sc in Department of Electronic Computer Systems Engineer at Technological Education Institute of Piraeus, Greece. “Power line comnunication (PLC) is the technology that allows data transmission over the existing Power Line network. Power Line can be the home power network or the national electricity transmission grid. The data that can be transferred is as diverse as its speed. With speeds of nearly 200Mbps, video transmission, voice, data and any other services can be transmitted successfully. This project includes the design of two modules (transmitter – receiver) implementing a serial communication over the Mains connecting a remote large display to a weighing machine.”

Via the contact form.

App note: Understanding multidrop address assignments for thermal sensors

appnote.

Here is a app note from Maxim on multidrop thermal sensing:

In many thermal applications, it may be desired to utilize multiple temperature sensors, placed in different physical locations, to monitor the operating temperatures in predefined ‘zones’ within the system. To accommodate this desire, many thermal products have the added flexibility of user-defined slave addressing.

A similar version was published in the March 2014 issue of Electronics Maker magazine.

Free PCB Sunday: Pick your PCB

STICKERS

We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Continue reading “Free PCB Sunday: Pick your PCB”

DIY PCB manufacturing tips

DIYpcb
Acidbourbon offers some tips on PCB manufacturing at home.

I’ve been manufacturing my own PCBs in my basement now for more than two years. In this article I do not want to give yet another explanation of the toner transfer method, but give you an overview of the techniques that proved to be of value for me. Especially if you just want to get started with toner transfer PCB production, take some minutes to look through my tips, maybe it will save you some pondering later.

Via the contact form.

Application note: WiFly WebScan

app_note

Here’s an application note from Microchip: WiFly WebScan (PDF!)

WebScan is a special firmware release based on the standard WiFLY firmware that is designed to run on all Roving Networks Wi-Fi™ modules such as the RN-171 and RN-131. The Webscan firmware adds Real-Time Location System (RTLS) capability and is designed specifically to address the key requirements in asset tracking implementations, cost and simplicity.
The firmware is designed to operate in the tag that is directly connected to the assets, when tags wake from sleep, WebScan measures the RSSI levels from the local infrastructure‟s access points. The calculated RSSI values are then returned to the asset management server in a TCP packet. Using simple triangulation algorithms, third party software can then be estimated with reasonable accuracy. Servers may use this information to display the location information with shipment records or serve websites that offer enhanced mapping capability.

Controller for soldering irons using the Hakko T12 type tips update

unisolder5f

sparkybg writes:

Soon there will be a new version. The most universal I can think of.

  • Isolated USB connection (HID class) for firmware updates, live data, and PID tunning.
  • Will be able to recognize unlimited number of instruments – can read resistor, 1-wire EEPROM or 1-wire MCU in the connector or handle. When MCU is used in the handle, it will be able to read the temperature in the handle also, for the best possible accuracy.
  • Will be able to control 2 heaters simultaneously, for microtweezers of any kind.
  • Will be able to read any TC or resistive (PTC,NTC) sensor, linear or not.
  • Sensor input can be wired freely, can be inverted or wired in differential configuration.
  • 2 sensor inputs have separate 4uA – 16mA precise current sources for resistive measurements.
  • Will be able to work with any voltage between 10 and 24 volts, AC or DC
  • OLED display option, for more information and better user interface on the station.

Unfortunately it became pretty complex, and not so cheap, but still much cheaper than many OEM controllers. I have just finished the PCBs. I will open a new thread when I have a working prototype.

Free PCB coupon via Facebook to 2 random commenters

probecable-yellow

Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Continue reading “Free PCB coupon via Facebook to 2 random commenters”

Week in (p)review April 04, 2014

hqbmap-600

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • Free PCBs via Twitter on Tuesday
  • Weekly roundup and preview every Friday

Building a 4bit / 8bit computer in CPLD

BkSHuZbIAAA_Ow9

Hackshed crew has been working on a homebrew CPU from scratch in CPLD:

Building things on breadboards is fine but I often find that I either need to pinch something from the design, I knock wires out of place or there’s some other reason that it gets destroyed. In order to get round this, I’ve started building a modular control panel for my ongoing project. I’ve named it…. The Carlputer… ahem.
The first thing I decided I just HAD to have is nipple switches (toggle switches). I love the look of the old Altair 8800 and wanted to have something similar so off I went to Aliexpress and ordered 100 switches for £18. Bargain.

Bus Pirate Demo Board 3: I2C Part B

Screenshot-2014-03-15-18.27.40

Andrew Rohne posted another article on Bus Pirate Demo Board I2C showing the MCP4725 digital to analog converter and the PCF8563 real-time clock. Check out the part A here.

Like the last post, the ground and Vin need to be connected, and VPU (the pull-up resistors) need to be connected to the Vin as well. CLK on the Bus Pirate needs to be connected to SCL, and MOSI on the Bus Pirate needs to be connected to the SDA pin. There are other connections that will be necessary and will be different for each.
Digital to Analog Converter-
The additional connection that needs to be made for this is the ADC connection on the Bus Pirate should be connected to the OUT pin on the demo board. This will allow you to see the output. As shown in this video by Mike Parks, it is pretty easy to address and use.

Tear down of a cheap external USB battery

charger

cpldcpu did a teardown of an external USB battery:

The device has a USB micro-b socket which is used as 5V input for charging, and a normal USB-A socket as 5V output. The output power can be turned off and on by a toggle button. There are LEDs to indicate active power out (blue) and charging (red) states.
The pictures above show the innards of the device. Most space is taken up by an ICR18650 LiIon battery, which are relatively common devices with 2600mAH. In addition, there is a tiny tiny PCB.  The rear side of the PCB is dominated by a 4.7µH inductor, which is part of the boost converter to convert the 3.7V of the battery to the 5V USB output.

Novena, the open source computing platform

novenalaunch-frontside

Bunnie has announced the launch of Novena, a new open-hardware computing platform:

Novena is a 1.2GHz, Freescale quad-core ARM architecture computer closely coupled with a Xilinx FPGA. It’s designed for users who want to modify and extend their hardware: all the documentation for the PCBs are open and free to download, and it comes with a variety of features that facilitate rapid prototyping.

Check out the video after the break. Continue reading “Novena, the open source computing platform”

Nixie bargraph clock

Nixie-Bargraph-Clock

Thereisonlyme wrote this Instructable detailing the build of his Nixie bargraph clock:

This is a cool Nixie Bargraph Clock that has an hour and minute tube, the heights of the plasma in each tube indicates the time. There are some wires wrapped around the tubes so you can easily see what time it is without estimating.  The electronics are tucked out of sight in a box out of sight so when you are admiring the clock you don’t see the modern electronics which adds a nice touch of class. There are full details on the build so you could build your own, please note that since there is a Nixie tube in the project high voltages in the range of 140 volts are present making it a dangerous project if you are not careful.

Via Hacked Gadgets.