This project is a high voltage plasma speaker that is using two mosfets in half bridge to drive the flyback transformer. This reduces the load on the FETs, and thus reduces the heat produced by them. To find out how plasma speakers work see the bottom of this page. [via]
A reliable Plasma speaker - [Link]
This project is a VU meter using 14 IN-13 bar-graph Nixie tubes. The producing effect is really nice. Each of the tube is connected on driving circuitry that include bandpass filters of 60, 150, 400, 1000, 2500, 6000 and 15000kHz pass. Then each filter output is converted to DC and converted from logarithmic to linear scale suitable for Nixie tubes.
Nixie VU meter - [Link]
This project is a Nixie Clock using 4 tubes and common components. This clock is designed to be easy-to-build and it’s build using two boards one over the other. Clock works at voltages from 7.5V to about 14V and consumes around 200mA. The shield board has 4 RGB LEDs under the Nixies that can be turned off if you don’t like how it looks. It shows time, full date and temperature.
Nixie Clock with 4 tubes - [Link]
This project shows how to build a Panaplex display using some electrodes and a jam jar as the vacuum chamber. Panaplex is a gas-discharge plasma display related to the Nixie tube. The builder, Lindsay Wilson, explains how it works:
The entire thing is based on using a jam jar as a vacuum chamber. Each of the cathode electrodes is made from a 2cm length of copper wire. A stainless steel M3 screw is soldered to the middle of the wire. This allows it to be screwed to the support plate, which is made from a piece of ceramic tile. It was very easy to drill the 3mm holes with a diamond drill – the tile is made from sintered ceramic powder and is quite soft. A solder tag is mounted on the back of each cathode screw which allows electrical connection to be made to the respective cathode.
Homemade Panaplex display - [Link]
After 2 long years of on-and-off work my coilgun project is finally completed. For anyone who doesn’t know what a coilgun is, it’s a gun that fires a projectile with magnetic force instead of gunpowder. The projectile from this gun won’t kill a person, but the electrical energy stored in the capacitors is 78 times the lethal amount for human beings so this is no toy.
Some technical data:
- Action: single stage, bolt
- Power supply: 12V NiMH battery (fires about 15 times/charge)
- Charging: 40 watt regulated ZVS flyback driver (charge time ~30s)
- Capacitor bank: 4x 3900uF @ 400VDC
- Stored electrical energy: ~1.25kJ
- Switch: SCR
- Efficiency: unknown, probably 1-3%
- Body: lightweight ABS plastic pipe and sheets
Portable 1.25kJ Coilgun - [Link]
Mark Rehorst build his own Van de Graaff generator and documented the procedure on the article below. Van de Graaff generator is a device capable of producing high voltages by collecting electrostatic charges on a large metal sphere. The high voltage generated is able to make peoples hair stand up! Check the article below for construction details. [via]
DIY Van de Graaff generator - [Link]
Multi-spark ignition is very useful especially in the case of startings at low temperature and at low rpm range. Basic idea, is to apply to spark plugs instead of only one spark, a spark-burst having big energy. In this case, combustion of air/fuel mixture is much better and the emissions are more reduced. In addition, through burning improvement, the consumption of fuel can be reduced.
Synchronized multi-spark module (SMSM) for Electronic Ignition Devices (EID) – [Link]
This is a fun and non-dangerous project for those people who like to throw projectiles magnetically. It simply works by placing a ferromagnetic projectile at one end of a coil and pulsing some power in it. The trick is to switch off power when the projectile is at the middle of the coil, there are some ways to do it but it isn’t important now. The second trick is to use a coil as close as possible to projectile to maximize coupling and the third to avoid saturation, that means keeping the current not to high.
Mini efficient coil launcher from disposable camera flash - [Link]