Ultrasonic Transducer Driver Amplifier Circuit

Hi MM, I used a 'burst' method of driving 200KHz and 30KHz transducers. The transducer pulse generator was from a square wave osc, tunable over a narrow range in order to get the optimum power out from the transducer. The pulse or burst width generator was adjustable from 100uSec thru 10mSec, this enabled a level of power control in the acoustic pulse. The transducer driver stage was a NPN power transistor driving a 1:3 or 1:5 transformer at 30KHz or 200KHz respectively, supply voltage 12V or 24V depending upon the required acoustic power. My product applications were for hydro-graphic depth echo sounders, working in water depths of 0.5mtr upto 400mres.

E Is you application bio-diesel.? Hi Eric, Isn't the number of cycles (burst) of 40khz determined by the length of the ON pulse? A 20ms pulse will have more cycles that a 2ms one (10 times more). The size of the Burst is directly related to the duty cycle.

Circuits Designed by Dave Johnson, P.E.: 40Khz Ultrasound Receiver A X100 transistor amplifier is followed by a zero cross detector circuit, using a voltage comparator. The output is a TTL logic signal, corresponding to the received 40KHz signal.. Apr 26, 2015 - 1) The ultrasonic transducer power supply boards found on eBay are, um. Different impedances to the driving circuit at different frequencies.

In order to increase the burst time, we need an amplifier that will take more power. Currently I can't get past a duty cycle of 1% without smoking the heatsinked Fet. EG: 5ms ON and 500mx OFF.

As I mentioned before, I dip all transducers to find their exact resonant TX frequencies and their band pass. Then I program the CPU to change frequency over the band pass. If the BP is say 2khz wide, I will step the frequency up by 100hz every few seconds.

That way I send multiple bursts to 20 different frequency locations, of which a few should be more effective in ringing the wafer. What do you think? I built a cat scarer at my last house. I didn't bother with trying to tune to the ultrasonic horn I had. I drove the secondary of a toroidal mains transformer using a low voltage drive at ~41KHz and used the primary straight across the piezo horn. Maybe not the most efficient, but it worked effectively and gave quite a nip when touched. What surprised me most was the frequency response of a 6.0.6-240VAC cheapo toroid was at such a frequency.

I've seen your flag on the marble arch Love is not a victory march It's a cold and it's a broken Hallelujah Hallelujah, Hallelujah Hallelujah, Hallelujah There was a time you let me know What's really going on below But now you never show it to me, do you? Download Hallelujah by Willie Nelson Willie Nelson Hallelujah lyrics Now I've heard there was a secret chord That David played, and it pleased the Lord But you don't really care for music, do you? Kolibeljnaya hyurrem oj lyuli mp3. EMD offers a premium experience that includes unlimited access to CD quality music. It goes like this The fourth, the fifth The minor fall, the major lift The baffled king composing Hallelujah Hallelujah Hallelujah Hallelujah Hallelujah Your faith was strong but you needed proof You saw her bathing on the roof Her beauty and the moonlight overthrew you She tied you To a kitchen chair She broke your throne, and she cut your hair And from your lips she drew the Hallelujah Baby I have been here before I know this room, I've walked this floor I used to live alone before I knew you. And remember when I moved in you The holy dove was moving too And every breath we drew was Hallelujah Hallelujah, Hallelujah Hallelujah, Hallelujah You say I took the name in vain I don't even know the name But if I did, well really, what's it to you?

It solved my cat problem BTW with me having to suffer the loud click when the device first powered the horn. I could have resolved this with a bit of signal/startup logic but never bothered in the end.

Summary 1) The ultrasonic transducer power supply boards found on eBay are, um. Unsuited for hacker use. 2) Despite being careful, I managed to burn one out. 3) Apparently, no one else has been able to get these to work, either.

4) I'm a total coward when it comes to high-voltage measurements. Hackaday Fail For, I had originally planned to build and describe two types of ultrasonic experiment kits: a 'simple' unit based on an eBay power supply board with a timed relay, which would be simple to purchase and assemble, and a 'designed' supply with adjustable power and microprocessor control. I've since played around with the ultrasonic power supply board that came with my transducer, and have concluded that these are pretty-well useless for hacker purposes.

Additionally, I managed to burn one out despite being careful. My explanation of why these boards burn out so easily is below, after some background info about tuned circuits.

(NB: Apologies for the large images - the system doesn't save the image size properly. It looks good while editing, but after posting the images go back to 'full size.'

) Powering a resonant circuit As mentioned in, an ultrasonic transducer is effectively a series resonant LC circuit: the piezo plate electrodes form a capacitor, and the resonating mass acts as an inductance. Since the transducer is an LC circuit, it presents different impedances to the driving circuit at different frequencies. At its resonant frequency (28 KHz), it will appear to be a 25 ohm load, and when driven off-resonance, it will look like 1000. And driving the device at an intermediate frequency will result in an impedance omewhere between the extremes. (The high peaks in the plot are the parallel resonant modes, which should be avoided. Most of the off-resonance areas are about 1000 ohms.) The eBay transducers are rated at 100 watts, so the next question is: 'What level of drive voltage is needed to push 100 watts through the device?'

Hi MM, I used a 'burst' method of driving 200KHz and 30KHz transducers. The transducer pulse generator was from a square wave osc, tunable over a narrow range in order to get the optimum power out from the transducer. The pulse or burst width generator was adjustable from 100uSec thru 10mSec, this enabled a level of power control in the acoustic pulse. The transducer driver stage was a NPN power transistor driving a 1:3 or 1:5 transformer at 30KHz or 200KHz respectively, supply voltage 12V or 24V depending upon the required acoustic power. My product applications were for hydro-graphic depth echo sounders, working in water depths of 0.5mtr upto 400mres.

E Is you application bio-diesel.? Hi Eric, Isn't the number of cycles (burst) of 40khz determined by the length of the ON pulse? A 20ms pulse will have more cycles that a 2ms one (10 times more). The size of the Burst is directly related to the duty cycle.

Circuits Designed by Dave Johnson, P.E.: 40Khz Ultrasound Receiver A X100 transistor amplifier is followed by a zero cross detector circuit, using a voltage comparator. The output is a TTL logic signal, corresponding to the received 40KHz signal.. Apr 26, 2015 - 1) The ultrasonic transducer power supply boards found on eBay are, um. Different impedances to the driving circuit at different frequencies.

In order to increase the burst time, we need an amplifier that will take more power. Currently I can't get past a duty cycle of 1% without smoking the heatsinked Fet. EG: 5ms ON and 500mx OFF.

As I mentioned before, I dip all transducers to find their exact resonant TX frequencies and their band pass. Then I program the CPU to change frequency over the band pass. If the BP is say 2khz wide, I will step the frequency up by 100hz every few seconds.

That way I send multiple bursts to 20 different frequency locations, of which a few should be more effective in ringing the wafer. What do you think? I built a cat scarer at my last house. I didn't bother with trying to tune to the ultrasonic horn I had. I drove the secondary of a toroidal mains transformer using a low voltage drive at ~41KHz and used the primary straight across the piezo horn. Maybe not the most efficient, but it worked effectively and gave quite a nip when touched. What surprised me most was the frequency response of a 6.0.6-240VAC cheapo toroid was at such a frequency.

I've seen your flag on the marble arch Love is not a victory march It's a cold and it's a broken Hallelujah Hallelujah, Hallelujah Hallelujah, Hallelujah There was a time you let me know What's really going on below But now you never show it to me, do you? Download Hallelujah by Willie Nelson Willie Nelson Hallelujah lyrics Now I've heard there was a secret chord That David played, and it pleased the Lord But you don't really care for music, do you? Kolibeljnaya hyurrem oj lyuli mp3. EMD offers a premium experience that includes unlimited access to CD quality music. It goes like this The fourth, the fifth The minor fall, the major lift The baffled king composing Hallelujah Hallelujah Hallelujah Hallelujah Hallelujah Your faith was strong but you needed proof You saw her bathing on the roof Her beauty and the moonlight overthrew you She tied you To a kitchen chair She broke your throne, and she cut your hair And from your lips she drew the Hallelujah Baby I have been here before I know this room, I've walked this floor I used to live alone before I knew you. And remember when I moved in you The holy dove was moving too And every breath we drew was Hallelujah Hallelujah, Hallelujah Hallelujah, Hallelujah You say I took the name in vain I don't even know the name But if I did, well really, what's it to you?

It solved my cat problem BTW with me having to suffer the loud click when the device first powered the horn. I could have resolved this with a bit of signal/startup logic but never bothered in the end.

Summary 1) The ultrasonic transducer power supply boards found on eBay are, um. Unsuited for hacker use. 2) Despite being careful, I managed to burn one out. 3) Apparently, no one else has been able to get these to work, either.

4) I'm a total coward when it comes to high-voltage measurements. Hackaday Fail For, I had originally planned to build and describe two types of ultrasonic experiment kits: a 'simple' unit based on an eBay power supply board with a timed relay, which would be simple to purchase and assemble, and a 'designed' supply with adjustable power and microprocessor control. I've since played around with the ultrasonic power supply board that came with my transducer, and have concluded that these are pretty-well useless for hacker purposes.

Additionally, I managed to burn one out despite being careful. My explanation of why these boards burn out so easily is below, after some background info about tuned circuits.

(NB: Apologies for the large images - the system doesn't save the image size properly. It looks good while editing, but after posting the images go back to 'full size.'

) Powering a resonant circuit As mentioned in, an ultrasonic transducer is effectively a series resonant LC circuit: the piezo plate electrodes form a capacitor, and the resonating mass acts as an inductance. Since the transducer is an LC circuit, it presents different impedances to the driving circuit at different frequencies. At its resonant frequency (28 KHz), it will appear to be a 25 ohm load, and when driven off-resonance, it will look like 1000. And driving the device at an intermediate frequency will result in an impedance omewhere between the extremes. (The high peaks in the plot are the parallel resonant modes, which should be avoided. Most of the off-resonance areas are about 1000 ohms.) The eBay transducers are rated at 100 watts, so the next question is: 'What level of drive voltage is needed to push 100 watts through the device?'