That little 0.25W thing isn't a speaker, it's a shrieker.
The digital clock radio that I bought for only $.99 has a bigger one (and makes a bigger shriek). :lol:
We can't hear frequencies from 25kHz to 50kHz so nobody makes a speaker go so high. An expensive tweeter might go as high as 25kHz but it is fragile and can't handle much continuous power. It can produce "tick" sounds loudly. A continuous loud tone would destroy it.
We can't hear frequencies from 25kHz to 50kHz so nobody makes a speaker go so high. An expensive tweeter might go as high as 25kHz but it is fragile and can't handle much continuous power. It can produce "tick" sounds loudly. A continuous loud tone would destroy it.
The 1st one have reps in USA, Canada and Latin America. They have extremely narrow-band resonance that would need very fine frequency tuning and matched devices for any range.
The 2nd one has no detailed spec's and you must buy a min of 10,000.
The 1st one have reps in USA, Canada and Latin America. They have extremely narrow-band resonance that would need very fine frequency tuning and matched devices for any range.
The 2nd one has no detailed spec's and you must buy a min of 10,000.
The larger good Murata tweeter is really good (if they didn't smooth its frequency response graph too much). It seems to need an awful lot of power for its fairly low volume output. They don't say what its capacitance is, which is probably pretty high, requiring high current at high voltage. Get many because continuously at full power it doesn't last very long.
The larger good Murata tweeter is really good (if they didn't smooth its frequency response graph too much). It seems to need an awful lot of power for its fairly low volume output. They don't say what its capacitance is, which is probably pretty high, requiring high current at high voltage. Get many because continuously at full power it doesn't last very long.
although i have no access to online shpping but now i am a bit HOPEFUL finding a thing like them here, i will go and see what kind of tweeter i can find,
if i could fnd a suitable tweeter then i must find a circuit to go it at resonant position, am i right?
I think to make a distance ranging system you need an object that can reflect ultrasonic waves. Then you "ping, ping, ping" the ultrasonic sender and enable the receiver in between pings to detect the reflections.
You need an ultrasonic oscillator and power amplifier that is gated by pulsing oscillator. The receiver is gated on by the pulsing oscillator inverted.