floated 1Mhz sine wave generator

[Finkl]

I have a problem to resolve.
I have a floated 1Mhz sine wave generator that output
100VRMS Max on 200 ohm load.
I need to measure the output voltage and the output currant
On the 200 ohm load.
Duos anyone have an idea what is the best way to do that?

 

[jiripolivka]

As the output circuit is coupled to the load with the T2 transformer, you can simply connect one of load terminals to ground. If your load does not allow you to do it, you must use 200 Ohm, 50W resistor (not wire-wound due to the high frequency) instead as a "dummy load".
Then you can connect an oscilloscope probe (rated to >100 V p-p) and measure the output voltage across the load.

To measure the current, you can add a 1-Ohm resistor in series with the load, again best to the grounded point. Again use an oscilloscope to measure the voltage across this 1-Ohm resistor to find the current.

 

[WimRFP]

Maybe OT, but what it the function of the cored inductors and polarized capacitors between T1 and T2? If the components behave as an impedance transformer, open load situation may result in high current in the push-pull stage.

 

[jiripolivka]

I never suggested to disconnect the load! I only suggested to ground one load terminal (T2 insulates the load), or use a dummy load if necessary.

 

[WimRFP]

@Jiripolivka: The issue regarding open load was for Finkl, sorry for the confusion.

 

[Finkl]

hi WimRFP
It’s my copy past mistake
I fixed the sketch to ceramic capacitor (LC filter).

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[FvM]

1 MHz is well in the available range of industry standard current and differential voltage probes. Specialized simple solutions like ferrite toroid current transformers can be considered, too.

 

[Finkl]

HI jiripolivka
Sorry but didn't mention that I need to
Measure the voltage/currant and use it
As part of the control loop ADC,MCU.
So I need to use amplifiers etc…
See the update sketch

- - - Updated - - -

- - - Updated - - -

HI FvM
Sorry but didn't mention that I need to
Measure the voltage/currant and use it
As part of the control loop ADC,MCU.
So I need to use amplifiers etc…
See the update sketch

 

[FvM]

Sorry but didn't mention that I need to
Measure the voltage/currant and use it

The suggested solutions applies basically nevertheless. If a certain load by the measurement circuit (e.g. 10 kOhm range) can be accepted, a RFtransformer preceeded by voltage divider should be considered for the isolated voltage measurement, otherwise differential amplifiers.

No idea if you need phase sensitive detectors/rectifiers to enable complex load impedance measurement.

 

[Finkl]

You mean to this?
Can you recomand on RFTransformer?

 

[FvM]

Yes, at least similar.

The current transformer should have the shunt on the secondary size and a respective windings ratio.
For the voltage transformer, I imagine a primary voltage divider with low output impedance, e.g. 50 ohms and a standard RF transformer, e.g. from minicircuits.com.

 

[Finkl]

hi FvM
I am not sure that I got you can you load a simple sketch?