Kapanadze/Kapagen Output Filter for Power Measurements

[F_Brown]

I would like to propose an output filter for Kapanadze/Kapagen style devices, which would filter the output of the device thus producing smooth DC, which could then be run into a resistor load across which voltage and current measurement could easily and accurately be made.

Attached is the circuit.  It consists of a bridge rectifier that is connected to the output winding of the original device.  The output of the bridge is then run through a classic LC Pi filter.  The 1H and 4,700uF values shown in the circuit should reduce all ripple to milli-volt and milli-amp levels when the output is in the range of 120V.  A step-down transformer or step-up transformer for that matter may be required between the output of the original device and the bridge according to the output voltage of the original device.

Best regards,

fred b

[gyulasun]

Hi Fred,

Your suggestion sounds good and hopefully many people will be willing to follow it but:

you may also wish to give pieces of advice as to the whereabouts of a 1 Henry coil or how to build such in case it is not off the shelf somewhere.  You may also draw attention to different power levels this filter coil (choke) should pass, preferably without too much saturation for its core.

One more thing: the suggested step-down or step-up transformer to arrive at a certain output voltage level (say 120V) can also be troublesome to build because the original output may include high frequency components which may be also useful but the a transformer if not a wideband power transformer may kill or decrease useful output.  And a wideband power transformer is also difficult to build or buy and expensive.

Again: I welcome your suggestion, however maybe an 1 Henry coil is too big and needs heavy wire with big core cross section area i.e. very expensive. Perhaps several core pieces from microwave oven transformers and the original primary coil(s) may make it much cheaper to approach, allowing a certain air gap in the core to handle core saturation to a certain level.
As to the step down or up transformer issue: a coil with less or more turns than the main output coil coupled strongly to it may do this job.
Other suggestions are welcome of course.

Greetings,  Gyula

[F_Brown]

Hi Gyula

You bring up a number of good issues.  I will try to address some of them.  Since each replication will probably be different, I lack the ability to recommend any particular off the self parts, and since I lack any idea the output voltage or current capability of any individual device I must leave it to the builder to properly select caps with sufficient voltage and ripple current ratings and the same for the choke for the device they built.   

A one henry choke with sufficient current handling ability say several amps at  400v would be kind of pricey to buy new.  Such item can usually be found in electronic salvage stores for reasonable prices, and are common parts for vacuum tube amps.  I would recommend people avoid grinding the welds loose and attempting to rewind MOTs.   If I was going to go that route, I would use an isolation transformer or some other transformer that was bolted together and lacked welded laminations for a rewind attempt.  Also, I have studied transformer design for years now, and properly designing and building such a choke is a complicated and labor intensive project.  Acquiring a pre-built part rated for the particulars involved will be much easier.

I wonder if high frequency loss would be significant with a low-frequency step down transformer, since Kapanadze himself uses a MOT in reverse to generate the LV to run his battery charger in one of his first videos.  I believe he had a bridge rectifier on that as well.  So that could be done, and then it would just be a matter of finding caps that could handle the voltage, motor run caps would do if they had sufficient voltage rating, as well as a choke that would handle the current.

Rectification could be done directly from the HV output of the device, that would retain as much of the HF content as possible, although then HV diodes would have to be used, as well as HV caps and choke, and meter.  As far as the meter goes a separate voltage divider could be built so that a regular meter could still be used.

I have seen many videos of replication attempts lighting up some lights to who know how much power.  I have seen people putting current and power meters meant for mains voltage and frequency on their devices.  Such meters are only accurate at mains voltage and frequencies.

By lowing the voltage and then rectifying the current.  Ordinary meters can be used to measure the resulting smooth DC with a good degree of confidence and repeatability. 

Best regards,

fred b 

[Hoppy]

@ F_Brown,

You give some good advice. Its all too easy to discover OU with the incorrect measuring instrumentation! 

Hoppy