ESP8266 mains energy monitor

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A ESP8266 mains energy monitor project by Brian Dorey:

 As the new solar logger did not have this functionality we decided to design a new data-logger that would measure not only the mains current usage but also keep track of the electric meter and gas meter so we can easily see how much energy we are using in the house.
The new mains energy monitor was designed to be a standalone box that would be powered from the mains and have sensors for the mains current, electric meter and gas meter. As we didn’t want to run any more wires around the house we also decided to make it wireless connecting to our network over Wi-Fi.

Project info at Brian Dorey’s blog.

Mullard 3-3 amplifier project (part 1)

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Dilshan Jayakody has published a new build, a Mullard 3-3 amplifier project:

Mullard 3-3 is quiet popular 3W tube amplifier introduced by Mullard Ltd in 1956. A schematic and design detail of this amplifier is available in “Mullard Circuits for Audio Amplifiers” book and in National Valve Museum article. This amplifier is based on EF86, EL84 vacuum tubes and EZ80 full wave rectifier tube. In this project we decided to construct this original Mullard 3-3 Amplifier with some slight changes and commonly available electronic components.
In our prototype we replace EZ80 tube with 400V 5A bridge rectifier which is commonly available in many electronic spare parts shops. Also we replace EL84 with 6P14P pentode and EF86 with 6J8 pentode. Both of these valves can directly use with this circuit and those values are available for lesser price than EL84, EF86 tubes.

Project info at Dilshan Jayakody’s blog.