Bipolar transistor switching +12vdc to -12vdc using arduino waveform generator.

I am trying to use an uno or mega to generate a tunable waveform (sine, square, triangle, but especially sawtooth) to achieve +/- 12vdc output respective to the waveform. I have read some topics talking about H bridges, but found nothing yet on my project exactly. Does anyone have any ideas or codes I can try?

Cannot be achieved with additional hardware and even then it will be with limited bandwidth. A decent SPI DAC will get you well into the audio range but you’ll need an amplifier get +/-12 volts output, an H bridge will not provide that ability.

What frequency range do you need and how much output current or power at +/-12 volts?

In the end, I will need to adjust frequency as well as the shape of the waveform on the fly. I would guess 20-40Khz and somewhere around 4-6 amps.

Look up X-Y problem. Then tell us what you want to do.

X= I would like to control an electromagnet for variable push/pull following the shape of the waveform generated by an UNO or MEGA. The attachment above is ideal if even possible.

Arbitrary waveform generators are available. See DDS devices.

24v p-p with 40khz fast risetime signals at 6 A driving highly inductive loads is a VERY serious power amplifier. Not a ten minute lashup.

Is it really necessary?

Allan

I like to believe it is necessary, I have thought about this project for years now. Do you think the waveform is possible to tune in? I will read the DDS section this evening. Another note, I can wind the magnet myself and 12vdc is another variable. So R and E are choices compared to I. Would this change the seriousness of the power amplifier?

A bit. But if you expect me or anyone else here to design it for you free, think again.

That's harder than a top-end audio power amplifier. And will probably involve a fair bit of magic smoke in development. For one thing, switching off 6A into a several henry load in 1uS (say) means dealing with a huge voltage transient. Remember V = L di/dt?

Allan

ps it might be worth buying a secondhand 200 watt audio amp and trying it. It won't meet your spec by miles, but at least it's a start.

I appreciate it. I have just begun trying to take this idea from concept to reality. Back to the lab!

Do you think the waveform is possible to tune in?

No, that rise time at that current and frequency is not going to happen in an inductor.

Mweisenbacher:
X= I would like to control an electromagnet for variable push/pull following the shape of the waveform generated by an UNO or MEGA. The attachment above is ideal if even possible.

Please identify the electromagnet that can change poles that fast.

Paul

1/ It ain't gonna happen. Not at all easily
2/ Only a very fast arduino (Due?) would help it happen.
3/ If you really want it to happen, take out a large checkbook and talk to me in 'gigs and collaborations'
That's a 6-month project and several 100k at a guess.

Got a couple of ideas.

I'm up for a challenge............

Allan