I hosted a webinar on March 10, 2023 on

"Ultrasonic Transducer Resonance Frequency Tracking"

You can watch the recording on my YouTube Channel here: 

https://youtu.be/f8sRapa-swM

Here is a link to the presentation notes.

Topics

In this webinar recording, I used an Arduino microcontroller to provide frequency control feedback based on current measurements.

I drove an atomizer transducer at a specified current level. I utilized a frequency generation IC (SI5351), an audio amplifier board to produce 90kHz-110kHz. I also used a hand wound transformer for impedance matching. Finally, a simple peak detect circuit conditioned the current signal to be read by the analog input of the Arduino.

Here is the outline of the webinar.

• 0:00 -Welcome to my 11th webinar
• 1:54 -Outline
• 5:07 -Choosing a transducer
• 7:47 -About Ultrasonic Advisors
• 8:57 -Block diagram of feedback circuit
• 13:25 -Drive circuit principles
• 18:25 -Feedback control with regards to impedance frequency response
• 20:39 -Impedance response of mesh atomizer with and without fluid
• 23:27 -Driving Amplifier
• 33:30 -Amplify voltage
• 36:30 -Transformer winding
• 39:09 -Walk through of experimental circuit setup
• 46:14 -Final circuit diagram
• 53:58 -Current peak detect circuit
• 55:42 -Arduino feedback loop code
• 59:30 -Oscilloscope readings
• 1:04:04 -Arduino serial monitor of feedback loop
• 1:06:02 -Questions and Answers

***Announcement***

My next webinar will be 11AM ET - April 14, 2023  "Implementing feedback loops for current and phase in an ultrasonic drive circuit"

Here is the link to sign up for the upcoming webinar: https://www.ultrasonicadvisors.com/monthly-ultrasonic-webinar