60Hz to 40Hz transducer

[fengzujian]

Dear professionals
I need to build a power tranducer to drive a eletromagnetic buzzer.The residential electricity in USA is 110V 60Hz, I need the output to be 110V 40hz in square wave with with limited output current.
How can I get the transducer, please help, thank you in advance. **broken link removed**

 

[goldsmith]

Dear fengzujian
Hi
Can you tell me a bit more explanations , please ? for example transducer of what thing what thing ? you told you need the out put of 110 volts 40HZ and of course square wave . with current limiter . it is simple to do . but if you tell me more about the required specifications , i can help you .
Best Wishes
Goldsmith

 

[fengzujian]

Hi,goldsmith
Actually, I'm a antenna designer.The project is a buzzer array work on 40Hz. The passive electromagnetic buzzer should be drived with the external signal with 40hz 110V AC, and the preferred waveform is not sine wave but half square wave. The question is if the power is 60hz 110v AC, how do I change it to the working power for the buzzer.

 

[goldsmith]

Hi again
It is not complicated ! are you familiar with SMPS and converter design ? If yes , at first , try to rectify and filter the 110 volts . and then use an H bridge with SPWM which has a 40HZ sine wave as message signal , and then filter it's out put . thus you will have a 40HZ sine wave with your desired voltage .
Best Wishes
Goldsmith

 

[sky_123]

Hi,

Are you sure that buzzer requires such a signal? If it does, then it is a very unusual device. I think it may work with the usual 60Hz 110V (unless of course you need 40Hz for some reason! : ) In which case, as a suggestion, you could use (say) a 12V solenoid and a 555 ic at 40Hz driving a MOSFET driving the solenoid.
EDIT: btw that transducer probably sounds at 120Hz.

 

[goldsmith]

Hi again fengzujian
Sorry , an error found in my latest post . i thought you need a sine wave , for your project ( for a short time ) . you can drive a mosfet as sky_123 said , with a TLP250 opto coupler which as a totem pole internally and then get your out put from source .
Best Events
Goldsmith

 

[fengzujian]

Dear goldsmith and sky_123
so your advice is first rectify the AC to DC, then invert it to 40hz signal, then rectify it to Square wave. The other method is transform the AC to 12V then drive a MOSFET with either a 555 ic at 40Hz or a TLP250 opto coupler which as a totem pole internally.
My question is the total amount of buzzers is about 100 pcs. So the average power consuming maybe more than 300w, and the average current maybe more than 2.5A, the instantaneous current maybe higher.I'm not sure the circuit can provide the enough current and still have the rated voltage of 110V.
The resonance of the buzzer may near to 40Hz, because another supplier show similar product with fundamental frequency at 50±5Hz
https://cosson.en.alibaba.com/product/540731861-210771881/mechanical_Buzzer.html
H bridge:

SPWM:**broken link removed**

 

[sky_123]

I think you've made some incorrect assumptions. The first buzzer is designed for 110V AC, therefore likely for 60Hz. You don't need a circuit, it just needs to be connected to 110V AC.
The buzzer in the link in your post #7 is designed for 220V, which is likely for 50Hz power systems.
These buzzers are designed for a mains signal. They don't need you to convert to a square wave. If they did, then no one would buy them.

 

[goldsmith]

Hi fengzujian
I'm agree with sky_123 . if that buzzer needs square wave, i don't think anybody want to buy that , too .

 

[fengzujian]

I understand your consideration. The company always build right in use item to facilitate the customer. I use the buzzer array the bombard a heated gas to excite it to radiate. The best frequency is 40Hz(maybe it's not the resonant frequency of the buzzer, but it's very near the F0). Giving the hysteresis existed, I think the prefered Voltage of Buzzer is positive square wave, it can provide the strongest response in mechanics.