35
votes
Why has my tweeter speaker burned up?
Your linked description shows that the tweeter is intended to be used with a woofer for music reproduction. The description doesn't cover use of the tweeter as a specialist ultrasonic transducer on ...
- 3,800
21
votes
Why has my tweeter speaker burned up?
It appears that the problem lies with the power ratings of loudspeaker components being the power rating of the system and not that of the individual component.
For example, in the 1970s, Philips were ...
- 17.5k
12
votes
What sensors to use to read gym machine selected weight
3 come to mind.
An IR encoder as RoyC mentioned. Paint the back or sides of the weights alternating white and black.
A camera as you already mentioned. OpenCV would make quick work of this. And You ...
- 72.8k
11
votes
Why has my tweeter speaker burned up?
I'm afraid that you are another Amazon victim. I note that you have linked to an Amazon ad rather than a manufacturer's datasheet which would explain how the device is rated and expected operating ...
- 171k
11
votes
Why has my tweeter speaker burned up?
The power ratings for audio equipment are often completely bogus. Check out the amount of copper in a 350W motor (and note that a speaker is also essentially a motor, only the motion is linear instead ...
- 25.7k
10
votes
Accepted
How do ultrasonic sensors differentiate between transmitted and received signals?
But the receiver and the transmitter are placed side by side. Won't the receiver immediately pick up the signal as it is sent? How does ignore the signal as it is sent, and record it only as it ...
- 22.1k
10
votes
Accepted
High pitch audio frequency measuring
Most common audio equipment is set to match human hearing, 20Hz to 20kHz is their operating range.
So you want to measure ultrasound, If you want only to measure high frequencies, you can use a bat ...
- 1,098
8
votes
Accepted
Boosting 5V/2A to +70/-70V for op-amp rails?
I would strongly recommend against attempting any sort of audio output transformer to boost the output of the op amp like is being suggested in the comments. Don't get me wrong, it is a perfectly ...
- 28.2k
8
votes
High pitch audio frequency measuring
By definition of the audio range for humans, beyond 20kHz is beyond audio. There are audio equipment designers such as Rupert Neve who believe the range could be wider, but this is not necessarily ...
- 6,030
7
votes
How do ultrasonic sensors differentiate between transmitted and received signals?
There are monostatic and bistatic ultrasonic transceivers.
Monostatic
Monostatic transceivers are single transceivers that do the transmitting and receiving. As long as the transmission stops before ...
- 109
7
votes
Measure distance using an ultrasonic sensor in a pipe
I assume the pipe is only to protect the sensor from environment noise.
If the pipe is not filled with anything, then just line the inside of the pipe with sheets of sponge or foam to eliminate or ...
- 3,766
7
votes
Measure distance using an ultrasonic sensor in a pipe
Ultrasound Sensors measure the distance by sending an ultrasound signal and measuring the time it takes to be reflected from the object and come back. The biggest problem are reflections inside the ...
- 126
6
votes
Accepted
Ultrasound transducer at different frequencies
820kHz and 2.5MHz (=3*820kHz) are eigenfrequencies of the mechanical system. You will be able to drive the transducer at any other frequency, but the damping will be greater by orders of magnitude, so ...
- 926
6
votes
How to control the driving frequency when working with high power ultrasonic transducers
An idea once I had, but never tried, is to treat an ultrasonic transducer like a high-power crystal oscillator.
Your typical crystal oscillator circuit looks like this:
simulate this circuit –...
- 14.5k
6
votes
What will increase output volume (dB) on a Piezo Transducer?
10 Vpp is NOT the same thing as 10 Vrms. In order to get the full output from the transducer at 10 Vrms, you're going to have to drive it with a 20 Vpp square wave, or a 28.3 Vpp sine wave.
With a ...
- 170k
6
votes
What sensors to use to read gym machine selected weight
I would look at it from a different angle and try to detect in which slot the metal pin is placed.
This is an easier task and could be done in several ways such as using proximity sensors or micro ...
- 1,181
5
votes
Can ultrasonic distance sensor be used to measure groundspeed?
I'm not aware of cheap ultrasound sensors that can measure the Doppler in the return signal. At the risk of answering something that isn't quite what you asked do you need ground speed or is air speed ...
- 6,902
5
votes
Why did my Ultrasonic Sensor HC - SR04 measured distance is less than half of the actual distance?
Figure 1. Oops!
It appears that your scope horizontal trace is not in cal mode so all your readings are unscaled.
There should be a cal test point - usually a 1 V, 1 kHz signal. Hook up the probe ...
- 171k
5
votes
How to remove turn on ringing/overshoot in MOSFET output for 1 MHz and 70V Switching?
what i have done 1. try to add resistor 1M or 10K in gate of MOSFET, the result : no output signal
You've done that what you shouldn't do! If you check the datasheet then you'll see that the input ...
- 30.2k
5
votes
Measure distance using an ultrasonic sensor in a pipe
You may very well need a completely different technology than the ultrasonic. Some type of focused and targeted sensor beam reflected back from a target on the distant object may be a possibility but ...
- 57k
5
votes
Why has my tweeter speaker burned up?
Impedance
I'm going to start by addressing only one (admittedly rather minor) point raised in the question--that of the impedance.
The impedance of a loudspeaker isn't a single fixed number. It's ...
- 3,434
5
votes
What drives mechanical piezo device ultrasound maximum (sound) power output - electrical power or voltage?
Transducers for use in water as projectors have a sensitivity specification called Transmit Voltage Response (TVR) which relates the rms voltage applied to give a Sound Pressure Level (SPL) at 1 meter ...
- 8,464
4
votes
Using PWM output from ATMega to provide external clock to external 3.3V device
If you follow your TDC1000-TDC7200EVM link, it takes you to the User's Guide. p35 shows the schematic for the EXT_OSC input. You'll see that it has a 51.1ohm load resistor across EXT_OSC input and its ...
- 22.2k
4
votes
What sensors to use to read gym machine selected weight
Put a small infra red reflector on each block and arrange these in a vertical line. Your sensor set up is an IR illuminator and a directional IR sensor (photo-diode or transistor in a tube) mounted to ...
- 8,505
4
votes
Accepted
Alternative to a potentiometer to regulate 50 W
Don't try to scale down the 50 W signal coming out of the driver. Instead, control the driver circuit to produce a lower amplitude signal.
This is the same concept as a volume control for audio. ...
- 312k
4
votes
How to amplify a signal for piezo transducer from 1 Vpp to 200 Vpp at 400 kHz and 500 pF load
As this is a fixed frequency application, tuning out the capacitance with an inductor would improve things dramatically.
There's a choice to either do this in parallel, and drive the resulting tank ...
- 162k
4
votes
Accepted
Refraction vs Reflection in Ultrasonic sensor for water level detection
You can neglect the part of sound intensity entering the water.
What happens at the surface is illustrated here:
(Source: https://de.wikipedia.org/wiki/Datei:Partial_transmittance.gif)
The more ...
- 16.2k
4
votes
Accepted
Unit of ultrasound A-scans
The amplitude is just arbitrary units for relative measurements only. The absolute values don't really matter all that much.
The peaks in the graph represent changes in tissue properties — ...
- 170k
4
votes
Deliver a 40kHz & >40V cosine wave to a transducer for communication
Your DC blocking capacitor forms a high pass filter in combination with the input impedance of the amplifier.
The input impedance is less than 100 ohms, giving a cutoff of over 200kHz.
Your DC blocker ...
- 69.1k
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