Hello,
I have an arduino uno outputting a square wave from +5V to 0 at 1.77 MHz. I want to know how i can amplify the square waveform to 12 VDC and 1A. I want to supply 12 V and 1 A to a piezoelectric disc (ultrasonic). Any help is appreciated. Should I use this circuit to add onto my microcontroller output? I found the attached design in another thread.

 

Using the Op-Amp circuit would work, but i would say is not necessary. You could use the Arduino to turn on a transistor instead.

 

That circuit will not get you an amp. The pictured TL082 will not come close. I would just use your Arduino to drive a simple logic level MOSFET which cost about a buck. A Google of Arduino to MOSFET will yield dozens of simple circuits. Here are some examples.

Ron

 

It is not going to be as simple as we wish it would be. This is 1.2 MHz, far out of the range of most monolithic audio amps, and it would require faster rise and fall times than one would expect from a MOSFET driving a resistor. Besides, this transducer will work best with a sine wave.

The circuit below is a class B piezoelectric driver and it is described in U.S. patent #4271371. <= link

https://www.google.com/patents/US4271371

I wonder whether the transducer really will take an amp with only a 12 volt signal. Is there an impedance matching transformer on that transducer, or is the transducer very large?

 

The sch shows khz is khz or mhz.

 

The TS's schematic showed 1.2KHz. Though, ultrasonic is more likely 40 KHz. Either way, a simple N-MOSFET driver should do the trick. To get max power, a simple H-Bridge would be even better but that's beyond the original request.