Function generator booster by Kiriakos Triantafillou – 20 September 2016

[Kiriakos GR]

Function generator booster by Kiriakos Triantafillou – 20 September 2016

This is one two in one DIY equipment:
1)   It is a Function generator booster based on bridge amplifier with split power supply.
2)   And also one Symmetric +15V, 0V, -15V DC source with 1.5A at its output.


For some time I was interested to boost the output of my function generator up to an output of 230 ~ 260 ACV.
My main goal was to be able to amplify wave-forms or signal in the range of 50Hz up to 3 KHz which is the bandwidth of Variable Frequency Drive controllers.

Most modern handheld multimeter for industrial use they come with Low-Pass filter so this to perform filtering of unwanted harmonics at about 600Hz up to 1 KHz.

The best way for me to evaluate the quality of those filters, or better say their filtering ability, was me to test them at close to rear situation.
And here it born my hybrid booster, half part of it is two TDA4020 them working as bridge amplifier up to 16V output, and other half of it, this is regular transformer working as step up.
Most tricky part for the success of this project was me to find the proper transformer with the ideal input resistance as primary coil.

Today I am very happy and very proud, that this design it does deliver everything that I could ask for.
Speaking of performance in wave-forms and pulses, it does that with respectable perfection.
Similar solutions in the market they are priced over 2000 EUR, and I am very happy that my DIY booster it cost me nothing at all regarding cash.

From my pictures bellow you may get plenty of ideas of what I did and how.
People with the necessary technical qualifications they will easily understand all details.
Thank you! 

[Kiriakos GR]

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[giorgos]

Great idea and construction.
I suppose that with this circuit you can work with highest frequencies too, up to 3 K you want, because this IC is designed for audio signals.
Did you check it? Also in low frequencies near 50 HZ how was the results?

[Kiriakos GR]

From 50Hz up to 5KHz output in volts this is stable.
For example if output voltage at 50Hz this is set to 230V  by simply moving to 3KHz output will become 243V AC.

I did note that at 10KHz there is a significant increase (peak curve), after 20KHz this magic boost it is not there any more 

My design this is hybrid,  transistors have their own ( Gain & Loss) curve,  this copper transformer has it own ( Gain & Loss) curve always in respect to operating frequency.
I do consider this specific marriage as successful as long optimum results delivered from 40Hz ~ 5KHz.

[overvolt]

Great project !!