rwilsford07 @ instructables.com:
A boost converter works in two stages, ON and OFF. In the ON stage the Semi-conductive Switch is conducting and current builds up in the inductor producing an electromagnetic field, this field stores energy. In the OFF stage the Semi-conductive Switch does not conduct and the electromagnetic field collapses. When the field collapses the energy stored in it can not escape through the Semi-conductive Switch so it goes through the diode and into the load/Capacitor at a much higher voltage. This happens several thousand times a second via the pulses from the NE555 Timer Chip and the result is being able to charge a high voltage capacitor from a low voltage source. Below is some aid for those of you who do not know electronics well.
DC-DC HV Boost Converter - [Link]
Nixie tubes need about ~180Vdc to light up and thus on most devices a DC-DC converter is needed. We designed here a simple DC-DC switching regulator capable of powering most of Nixie tubes.
The module is based on the MAX1771 Step-Up DC-DC Controller. This controller works up to 300kHz switching frequency and that allows the usage of miniature surface mount components. It accepts an input voltage from 2 to 16.5V and the output is factory configured to 12V. In this module the output voltage is configured higher at ~180Vdc using external resistors and a potentiometer.
HV Nixie DC-DC Power Supply - [Link]
Andrea Biffi build a nice vertical nixie clock using ATmega8 mcu. He writes:
After the success of my first nixie clock made out from a rosewood block, I decided to lose no time and to carry on with the next one. As some of you guys already know, or imagine, lately I’m indeed a little bit addicted to nixie-mania. I’ve bought many nixie tubes on eBay, and I experienced in electronics so to build my own high voltage power supply and then the ultimate nixie clock circuit. Digits for this clock are nice rounded and fully transparent IN-4 tubes, the same I used in the first model, but as I previously announced, I aligned them vertically, so to read from top to bottom hours, minutes, and seconds. Indeed you will see the undeniable influence of Max Pierson’s vertical clock. I guide you now through the full process to make your own unique nixie clock.
Vintage style nixie wall clock - [Link]
I always wanted a spot welder, so I decided to built one. I wanted to build a capacitance discharge one but I couldnt afford for the capacitors at this time. So this is a controller for a dual pulse spot welder with some few extras:
- It has a zero cross detector. You could power the transformer at zero cross or dim the transformer if you like
- The transformer is triac controlled
- It has an hd44780 interface
- An spi interface for single thermocouple
- Peak detector of a current transformer
- Isolated foot switch
- Voltage monitor with opmaps
- An attempt to sense when the user tries to weld
- Single rotary switch for operation and single rotary encoder for setting up
MCU Controlled Spot Welder - [Link]
This is an instructable for making your own PWM (Pulse Width Modulated) flyback driver!
Simple PWM Flyback driver tutorial - [Link]
How to generate high voltage DC with a Cockcroft-Walton Multiplier circuit. a.k.a Cockcroft-Walton / Villard / Greinacher Cascade
EEVblog #469 – Cockcroft-Walton Multiplier - [Link]
I’ve recently become interested in Nixie tubes. Nixie tubes are neon filled glass tubes that contain cathodes in various shapes, numbers being the most common, and a mesh anode. Passing a current through the cathode causes the neon gas to ionize which makes it light up.
The problem with these tubes is that they voltages of around 170V in order to ionize the gas. Fortunately, most tubes only need a few mA which makes the supply design simpler and easy to run off a wall wart.
A low cost Nixie Tube Power Supply - [Link]
Dual-Resonant Solid State Tesla Coil (DRSSTC). Shane writes – [via]
It’s been a long time since I built something that isn’t a robot, a motor controller, anelectric vehicle, or a multirotor. Also, the Edgerton Center Summer Engineering Workshop (responsible for the DIY Segway, BWD Scooter, Cap Kart, and tinyKart) isn’t running this year, so I feel the need to take on a summer project of my own. Inspired by the work of MITERS regulars Tyler, Daniel, Bayley, and Ggy, I’m attempting to build..
Specifically, I’m building a Dual-Resonant Solid State Tesla Coil (DRSSTC). Tesla coils generate high voltage and pretty sparks using electromagnetic induction. They’re loosely-coupled air-core transformers where the world is your output load. (Or just the toroidal “top load” and the air around the Tesla coil.) “Dual-resonant” implies that both the primary and the secondary form RLC series resonant circuits, tuned to about the same natural frequency. “Solid state” implies that the primary circuit is driven (near resonant frequency) by transistors, usually IGBTs although I will be starting with MOSFETs.
Building a Dual-Resonant Solid State Tesla Coil (DRSSTC) - [Link]
Over the past few years, I’ve built up a few battery packs for myself and for other people. Most of them worked fine – in fact, one of the first packs I built over five years ago is still in service, working fine in a torch in the bottom of my cupboard.
The big problem with soldering to batteries is that you tend to damage the plastic separator, and the cell seals. This – as you might guess – is not a Good Thing™. In some cases, solder can splatter over the cell’s pressure relief vent. There’s a reason the datasheets make a big fuss about the vent – in an overpressure situation, the vent is used to release the excess pressure in the cell. Needless to say, blocking the vent with solder is never a good plan, unless you’re trying to get a Darwin Award, or you happen to enjoy watching your battery pack undergoing rapid, uncontrolled self-disassembly.
In industry, resistance welding is used instead of soldering. Not only are the welded joints smaller than solder blobs, but they cause less damage to the cell. The only problem is the cost of resistance welding equipment. A low-end resistance welding machine can cost upwards of GB 2,000.
The Poor Man’s Battery Tab Welder - [Link]