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Old 09-30-2017, 03:54 PM
serendipitor serendipitor is offline
Join Date: May 2014
Location: Western Washington
Posts: 41
More comments on Al's diagram


1. The SG3526 PWM generates two phase pulses of varying width, which through several stages of level shift and current boost will alternately switch on and off the main power transistors at the transformer primaries. This will give an AC waveform at the secondaries that is rectified by the full wave bridges and summed together for the final output. According to the Gray patent, this is used to charge capacitors in a stepped voltage waveform which are then discharged through inductors. It is not clear where the "cold electricity" aspect enters the picture. I think the secondary windings may be critical to this, and would be arranged so as to deliver sharp sliver pulses to the rectifiers, as is called for in Tesla's methods. It is not clear if Al's example has this function or not.

2. The SG1627, in conjunction with the small red encapsulated transformer, is simply generating a secondary supply of +5VDC and -5VDC. Those voltages are used for the driver bias on the level shifter stages, and the +5VDC supplies VCC to the SG3526.

3. The final stage of the driver path, labeled Ch1 and Ch2, are standard totem pole configuration, the PNP devices on the top, and NPN on the bottom. The emitters of the bottom pair are tied to the -5VDC supply, so as to permit more rapid and complete cut off the main switching transistors. This would also be a noise consideration perhaps, given the level of transients going around the device.

4. The winding labeled as "transistor trigger coils" is not that, but is actually the voltage sense and feedback winding. Its output is full wave rectified, filtered and applied through the pot to the Error input of the PWM controller, allowing regulation of the final HV.

5. There are some snubber RC's here and there which indicate that there was some effort required to control the voltage spikes from getting too high, as was normal practice for that time.

6. The primary windings of the main transformer are identical, but are energized with opposite polarity and alternating phase (i.e. one winding at a time) and thus produce AC pulses in the secondary. That the four layers of copper ribbons are touching looks not to be significant. They are all shorted at the ends, so insulating the layers would not likely have any effect. To investigate if the configuration of the windings is indeed an example of the theory that is described in the presentation, I am in the midst of creating a smaller version without all the regulation circuitry, and see if any anomaly is apparent.

Given that this power supply was used to charge capacitors, it's function could be duplicated in a variety of ways, as was shown in Mark Mckay's presentation. Certainly the engineer (probably Hackenberger) that designed the circuit knew what he was doing with conventional switching. The key point to focus on would be the main transformer, as far as I can see. The question is how does this create the "cold electricity" that is key to the technology? Tesla's technology was completely concerned with pulsed DC and its effects, so this power supply technique derives from that method.

Last edited by serendipitor; 10-02-2017 at 08:06 PM.
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