Saturday, 12 June 2010

Bedini `SSG´ Circuit

Animation of the Bedini `SSG´ Circuit

The Bedini “Simple School Girl´s” circuit is so named because it was constructed by Shawnee Baughman of Idaho in 2000 and won 1st prize in her school science fair.

The history of this motor design goes back much further, probably to 1974, when it was patented by Roger Andrews of Salem, Oregon as a novelty electric motor. (Ref. : Patent 3,783,550)

This is a relevant extract from his patent :




The moving magnetic lines of force provided by the spinning magnet top cuts the turns of the coil and thus induces a current in the coil. As is well known, the flow of current through the coil is reversed when the turns are cut by the lines of force associated with the opposite poles of the magnet. Thus, in one direction of current flow through the base-emitter of the transistor switch, the transistor is turned on momentarily to connect the battery 18 across the coil 16. A pulse of battery current thus is applied momentarily through the coil, whereupon the latter produces a magnetic field which is imposed upon the spinning magnet top in such manner as to accelerate the spin of the top.

The Bedini SSG motor, to all intents and purposes, is identical to that patented by Roger Andrews. It is based on what is commonly known as a `blocking oscillator´.

Blocking oscillators are often used as voltage converters / simple switch-mode power supplies; for example fluorescent light inverters. For many, it will be recognized as the circuit for a `Joule Thief´.

Many people have made `strange´ observations about the behaviour of the Bedini SSG Motor :

“The weird thing is that the amount of current required to drive the rotor goes DOWN when you bring the generator in to play or add a load.”

“Even weirder is that the rotor doesn’t appear to be strictly necessary for the battery charging side of things. If the coil and associated electronics are used on their own, or with the application of a magnet on the top and bottom of the coil, induces self resonance and the charging process still takes place.”

The Bedini SSG Motor is a mechanically triggered blocking oscillator. By careful coil design or the addition of a potentiometer, it is arranged that the motor is close to self-oscillation. As the transistor starts to conduct, current begins to flow in the inductor’s power coil which induces an increase in voltage in the trigger coil. So the transistor is driven harder into saturation by this feedback loop. In the absence of this positive feedback, the trigger coil would not have the sensitivity needed to react to the change in magnetic flux as the rotor turns.

With the SSG, this sensitivity is adjusted by the potentiometer. At one extreme, there is insufficient transistor base drive and the motor will not run. At the other extreme, the circuit will self-oscillate - marked by a step in power consumption. The neon bulb will illuminate and `battery charging´ is possible. (For those without the luxury of an oscilloscope, a domestic radio, tuned to 200KHz or thereabouts, can provide an audible clue as to what is happening.)

Many SSG enthusiasts refer to this point just before self-oscillation as the `sweet-spot´.

When a load is applied, this balance is altered - the response of the power coil changes and this is reflected in the amplitude / shape of the trigger pulse drive to the transistor - the power consumption will decrease.

Voltages produced by a blocking oscillator can be enormous and many hundred volts are readily achievable.

So what happens to the `charge battery´ when it receives a high voltage pulse ? The answer is that the battery is desulphated. Accumulations of lead sulphate are stripped from the battery plates, allowing the battery to perform better. This is the crux of the Bedini Motor myth - it can desulphate a lead acid battery making it work more effectively - it is NOT a true battery charger !

So if you really need a battery desulphator then here is a simple example - it has no moving parts and is probably 100% more effective ! This example is typical, deriving the power from the very battery that it is rejuvenating !

It costs very little to make and there are many kits and products available that are tried and tested over many, many years - it is not new technology - it is as old as the lead acid battery itself - it is not `Energy From The Vacuum´, it is simple text book chemistry - lead sulphate (PbSO4) !

The really wierd and strange discovery is that Bedini and Lindemann produce and sell desulphators ... and despite all of the claims that magnetic motors are the panacea for the world´s energy crisis there is not a magnet or moving part in their design !

Energenx Renaissance Charge Tesla Chargers

The above is `The Classic´ RC-2A12 desulphator / charger - `Compact, Affordable Radiant Power for 12V Batteries´ at only $260.00 ! (That´s a lot of batteries to recover !)

Whilst over on , desulphators are available for less than $30.00 but they don´t have that magic ingredient - `Radiant Power´ !

Later entries will explore some design considerations to improve system performance and efficiency. Aspects relating to battery charging / reconditioning will not be investigated. These motors are really fun, so let´s make them run faster and longer using less power !

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