Trying to make an Arduino Mosquito Repeller like this:
https://www.instructables.com/id/Arduino-Mosquito-Repeller/

which used digital pins 9 and 11 directly drive two piezoelectric ceramics.
my question is, is it possible to enhance the piezoelectric ceramic's power , I mean to Increase it's function range and how?

Thanks.

 

The only way is to use a set of Cmos Nand gates CD4093 on a 12V supply and that will boost the output voltage.

 

which used digital pins 9 and 11 directly drive two piezoelectric ceramics.
my question is, is it possible to enhance the piezoelectric ceramic's power , I mean to Increase it's function range

Of course it's possible.

and how?

How? Drive the piezo elements from a higher voltage. One way to do this is to use a pair of MCP1406 (or equivalent) MOSFET gate driver ICs to boost the signal level from the Arduino pins to a higher level, which can be up to 18 volts.

 

The only way is to use a set of Cmos Nand gates CD4093 on a 18V supply and that will boost the output voltage.

Thanks
I don't have a CD4093 handy, seems its function is to boost a high voltage, can I use a Transistor instead of or just use a high input voltage say 18V and low cycle PWM?

 

Of course it's possible.


How? Drive the piezo elements from a higher voltage. One way to do this is to use a pair of MCP1406 (or equivalent) MOSFET gate driver ICs to boost the signal level from the Arduino pins to a higher level, which can be up to 18 volts.

I used the below circuit and changed the input V from 5 V to 24 V, the sound no much changes, why?
The pots vary the PWM frequency and cycle.

 

I used the below circuit and changed the input V from 5 V to 24 V, the sound no much changes, why?
The pots vary the PWM frequency and cycle.

View attachment 180800

You need to connect a pull-up resistor between the FET gate and +5V to get it to operate correctly. Try a 470 ohm resistor and see what difference it makes.

 

You need to connect a pull-up resistor between the FET gate and +5V to get it to operate correctly. Try a 470 ohm resistor and see what difference it makes.

Thanks
I hooked a pull up resister and no much change.

 

I used the below circuit and changed the input V from 5 V to 24 V, the sound no much changes, why?
The pots vary the PWM frequency and cycle.

View attachment 180800

Because you are only pulsing one side of the piezo, you need a Bridge formation with four transistors or two Nand gates, ...

 

Look in Google. Several tests have shown that ultrasonic mosquito repellers DO NOT repel mosquitos and actually attract some mosquitos.
Since you cannot hear them, many of them do not produce ultrasonics anyway. They are just a scam.

 

View attachment 180802

Because you are only pulsing one side of the piezo, you need a Bridge formation with four transistors or two Nand gates, ...

Thanks.

 

Look in Google. Several tests have shown that ultrasonic mosquito repellers DO NOT repel mosquitos and actually attract some mosquitos.
Since you cannot hear them, many of them do not produce ultrasonics anyway. They are just a scam.

Yes, there are lot of different sayings.

 

View attachment 180802

Because you are only pulsing one side of the piezo, you need a Bridge formation with four transistors or two Nand gates, ...

No. The CD4047 outputs are already both in a bridge (Q and Q-not) but the current is very weak.

 

No. The CD4047 outputs are already both in a bridge (Q and Q-not) but the current is very weak.

I know, i was trying to find a Nand gate Complimentary Output but couldn't find one...

 

Thanks
I hooked a pull up resister and no much change.

Have you checked the spec of the piezoelectrc speaker you are using? You have probably reached it's limits and will need to use a larger one if you want more sound from it

 

Have you checked the spec of the piezoelectrc speaker you are using? You have probably reached it's limits and will need to use a larger one if you want more sound from it

Thanks.
That means the large the disk size, the strong the DB? or drive current effect?

 

That means the large the disk size, the strong the DB? or drive current effect?

Think a second... Hmmm... larger disk = more surface area K then larger surface area = more air pushed and more air pushed =?

 

A low frequency needs a large speaker, a high frequency tweeter works best with a small speaker. This ultrasonic frequency is much higher than high frequency audio so the size of the piezo is fine.
A piezo has high output resonant frequencies with low levels in between. Simply tune the frequency for maximum output level.
Here is an example of the frequency response of a piezo transducer. The sound levels are very different when the frequency is changed.