Amber House

15/05/2015

The Science Museum at Wroughton has very recently acquired a beautiful exhibit from a British 16kHz Transmission Station that was set up in 1926 and decommissioned in 2003. The object shown is the tuning inductor. The combination of very low frequency and high power levels makes everything big. There is no less art in this than engineering.

https://www.youtube.com/watch?v=L3Ux9dKgRi8

Rugby Radio Station began sending messages around the world in 1926. These enormous coils were part of the station's original transmitter (GBR), and can be s...

04/05/2015

640Volt inverter. Busbar, IGBTs, snubbing capacitors, smoothing capacitors and balancing resistors can all be seen here. This is by far the most powerful inverter we have built to date. Testing to follow soon..

30/04/2015

We have a new device under development which will require switching immense current levels (>700amps) at relatively high frequencies. We have two DC busbar topologies we're working on at the moment, one of which is shown here. The main endeavour in such designs is to minimise inductance as much possible. The busbar's geometry is central to this end, and a basic rule of thumb is that the shorter, the better. Even the slightest inductance can create voltage overshoots that could ultimately destroy the switching element. The setting shown will be subjected to a dc voltage of 640 Volts.

27/04/2015

Our Jacob's Ladder is complete with its Sci-Fi artistic production. The device exhibits the buoyancy of plasma using a V-electrode and a 30kV generator. All circuitry is safely tucked inside the sphere, while the lower transformer model is purely for dramatic effect.

17/02/2015

Sphere is taking color now after the circuitry has been installed and surface worked out to a fine level of smoothness.

15/02/2015

The V-electrodes have been installed at the top of the sphere.

13/02/2015

The ignition coil driver we've built will be connected to a V shape electrode setting (Jacob's Ladder). The clip shows a previous test we did where electrodes had this V-geometry. Arcing initially happens along the shortest possible path (lowest point), then due to buoyancy, plasma floats to the top until it reaches a point where the electrode separation is too wide for arcing to be maintained.

It is worthwhile remembering that the term 'Electric Arc' was coined because plasma literally assumes an arc-shape when ignited between two electrodes; again this being due to buoyancy effects

10/02/2015

Following on our coil driver circuit, we've built a spherical compartment to house the electronics. It's larger than the circuit actually requires, but it's more designed for artistic effect than volumetric economy.

The sphere is made of fiberglass and was split in half during its making before being reunited with itself. There are two circular trapdoors on opposite sides to enable access to the sphere's entrails.

07/02/2015

Our 20kV tentative coil driver has seen some considerable development and has hence earned her place on a fixed copper board. This board was created a couple of weeks ago when temperatures were significantly low. The way temperature affects end-results in photolithography is more severe than many would think. We had to carefully alter both developer density, etchant composition and exposure times to accommodate for the onset of winter. Obviously, getting a better heater for the lab would do the trick more easily, but we like sophisticated solutions.

06/02/2015

Good morning. Here's a capacitor bank we designed and assembled for an induction heater carrying currents of around 400A at frequencies slightly below 100kHz. The geometry is designed to optimize current sharing.

In general, a capacitor present a few millimeters closer to a load than his counterparts would tend to carry higher currents than the ones 'lagging' behind. That capacitor -in absence of optimization- would be the first to fail; consequently setting off a domino sequence as the remaining capacitors are burdened harder and harder with every additional failure.

21/12/2014

Pencils are mostly graphite and have resistances -from tip to bottom- of around a few ohms. Resistance actually varies with pencil grade (H, HB, B ,2B, etc..) with darker grades having lower resistance. We've done some adjustments on our HV circuit and have used pencils for electrodes today.

The pencil has literally become mightier than a sword. (Or of comparable might if anyone reading this is in a pedantic mood)

18/12/2014

Back to an exhibit that has been on hold for a while. Part of the device's operation requires generating small cute voltages of around 20kVolts. The circuit makes use of flyback transformers to achieve this. This is a nice photo we took while testing circuit functionality. The sharp threaded nature of the electrode enables multiple arcs to coexist simultaneously. We'll be posting more on this exhibit as it develops in the coming days. Have a nice weekend!