Need Help Converting 150,000hz 3.3V 19.38mA DC Square Wave into 20Volt .2A A.C Square Wave

WBahn

Joined Mar 31, 2012
26,063
Where's the 19.38 mA figure coming from?

What is a "DC Square Wave" and what is an "A.C Square Wave"?

Do you mean that you have a signal that goes from 0 V to 3.3 V and at 150 kHz and is capable of delivering up to 19.38 mA (and is that peak current, average current, rms current, or what)?

Do you mean that your output goes from -20 V to +20 V at 150 kHz and needs to be able to deliver 200 mA of current (and, again, is that peak or rms current)?

What kind of power supplies do you have available?
 

Thread Starter

z7d8tsg87oh2g92h9p38fh

Joined Oct 26, 2018
17
Hi Everyone, I'm Dan,

Answers to you questions:

Arduino Due.

DC Square Wave means 3.3 V then 0V then back to 3.3V etc
AC Square Wave Means 3.3V then -3.3V then back to 3.3V etc

For the 19.39mA, that is just what my multimeter says is the ampere output of that Pin of the Arduino Due. I don't walk to talk about the microprocessor intricacies right now, already was an sufferable pain.

Yes that is exactly what I need. A 20V P2P 150khz A.C Square Wave with a max output of 200mA

I have an old laptop Charger: It is DC 32V 720mA LPS

Thanks for the Help Guys!
 

WBahn

Joined Mar 31, 2012
26,063
Hi Everyone, I'm Dan,

Answers to you questions:

Arduino Due.

DC Square Wave means 3.3 V then 0V then back to 3.3V etc
AC Square Wave Means 3.3V then -3.3V then back to 3.3V etc

For the 19.39mA, that is just what my multimeter says is the ampere output of that Pin of the Arduino Due. I don't walk to talk about the microprocessor intricacies right now, already was an sufferable pain.

Yes that is exactly what I need. A 20V P2P 150khz A.C Square Wave with a max output of 200mA

I have an old laptop Charger: It is DC 32V 720mA LPS

Thanks for the Help Guys!
Your 32 V charger isn't going to do it by itself, since you need an output swing of 40 V and will need some overhead above and beyond that.

I assume your current needs are bipolor? Meaning that your circuit needs to be able to source 200 mA when it's output is positive and sink 200 mA when it's negative.

Are the ±20 V outputs constant (meaning that the amplitude of the squarewave doesn't change)?
 

Wendy

Joined Mar 24, 2008
22,155
The key to this wattage)P=volts x Amps, You cannot get more power out than you put in, reconcile this and the problem is doable, Otherwise you are talking over-unity ) or perpetual motion)
 

ebp

Joined Feb 8, 2018
2,332
Provided the load has no other connection to the circuit (that is, it is "floating") you can produce AC into it with an H-bridge running from a unipolar power supply. There may be integrated H-bridge power ICs that will handle that voltage and current, though the frequency is high relative to the typical application of many such ICs (motor driving). H-bridges can be built with discrete components, but for 150 kHz it not really simple. If the peak voltage must be 20 V, then the supply voltage must be 20 V or just a little more. If the 20 V must be very accurate then the circuit becomes a good deal more complex and beyond what I would recommend even to someone with a reasonable amount of knowledge and experience in designing and building circuits.

The current you measure from an I/O pin of a microcontroller is probably quite meaningless in terms of the ability of the pin to drive other circuitry. You most certainly will not get 3.3 volts output if the current from the pin is 19 mA and the supply for the processor is 3.3 V.
 

Thread Starter

z7d8tsg87oh2g92h9p38fh

Joined Oct 26, 2018
17
I was planning on using my current Laptop charger with a simple Voltage Doubler Circuit like below, but without the switch of course. I can always just buy a A.C To D.C Converter that is at whatever V and A that you guys recommend if needed too.


https://www.instructables.com/id/DC-DC-voltage-doubler-simplest-possible-circuit/


I have already bought for this project: BS170, Tip41AG and TIP42AG, 2N3904, PN3563, FCPF380N60-F152,
and 3x TL081CP.

My current requirements are indeed bipolar. I tried making a H-Bridge with the FCPF380N60-F152's, but the signal was too unclean and the mosfets were too slow.

There is variable impedance with what this will be connected to (Which is a transducer resonance experiment). The Amplified Signal being created by a Large Wave Function Generator (showing ideal states) is: Ideal Voltage Graph is A.C square wave, and Ideal Amperage Graph is A.C Triangle Wave
 

ebp

Joined Feb 8, 2018
2,332
Which circuit? The one designed by crutschow who happens to be a major contributor here at AAC?

None of us can see any details in the circuit without being members at edaboard.
 

Wendy

Joined Mar 24, 2008
22,155
Click on the attachment to get the URL address and put it between the(img) url address(/img) using brackets instead of parenthesis. Most moderator tend to like help users on sites like this
 

Thread Starter

z7d8tsg87oh2g92h9p38fh

Joined Oct 26, 2018
17
Below is a circuit for Driving a H bridge with 2 Optocouplers (File called Other Solutions)
I haven't tried it yet, but I see no reason why it cannot work.

Also Below is a Circuit for a Transistor Full Bridge

This following link is of a LTC444# circuit I got from my post at eevblog - that apparently could work too: https://www.eevblog.com/forum/rf-microwave/need-help-converting-150-000hz-3-3v-19-38ma-dc-square-wave-into-20volt-2a-a-c-s/?action=dlattach;attach=558955

Apparently, there are also many Full Bridge Mosfet Driver Chips Out there on the market, that can be easily fashioned for this. I'm not sure, I don't have tested and documented proof of this yet.

Anyways,
Which circuit do you guys think is best for efficiency?
thanks
 

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