Home made VLF? or DC Megger?

[meeko]

Hey,

I am currently looking into creating a tesla coil, and now that i have gotten started, i would rather build a VLF test set, since they are quite rare around here.

Was wondering if anyone here new if you could make a vlf test set with a high voltage transformer, operating with regualr 120vac, 15A.

and to measure the low frequency and display output with an osciloscope i presume?

I could calculate how the vlf could input a specific chosen voltage from a variac, and measure the current produced, to give me the capacitance, and resistance value of a high voltage cable.

anyone have any ideas on building one of these? i have used them many times before, but regret not taking it apart as it is going to be a fun project to make.

any help on builidng any part of a vlf would be greatly appreciated.

 

[davidbeach]

A transformer can't change frequency.

 

[DTR2011]

This may turn out to be an expensive project. You will need your frequencies of 0.1Hz, 0.05Hz, 0.02 Hz. Your output transformer needs to be designed to handle the V/Hz range you expect. Some block diagrams are available here . There are many manufacturers of VLF test sets available. Your input power specifications are fairly standard, but I think things will get costly when looking for the HV components. You will very likely need oil filled equipment. Additionally, for meaningful test results from your source, the source needs be have very low PD characteristics.

Some design parameters you will need up front are your intended voltage (peak) and load (capacitance). I can not stress the safety aspects enough.

 

[VEBill]

"Some block diagrams are available here..."

I especially like the truck.

 

[meeko]

woow! good read!

I cannot beleive that how expensive a VLF test set is! I rented one and used a few times, and would like to purchase one now, but at 32 000$, i find it would be fun project to make one. but alot more complex than a tesla coil.

Thanks for the info! any more anyone?