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feature
Active buzzer features:
- Also known as DC buzzer
- contains a multivibrator
- As long as the rated DC voltage can be sounded at both ends
- Simple drive control
- slightly higher price
Passive buzzer features:
- Also known as AC buzzer
- no internal oscillator
- A square wave voltage of a specific frequency needs to be applied to both ends (note that it is not AC, that is, there is no negative voltage)
- Reliable, low cost, adjustable audio frequency
the difference
1. Impact source
The "source" here does not refer to the power supply, but the impact source. That is to say, there is an impact source inside the active buzzer, so it will beep as long as it is powered on.
There is no impact source inside the passive buzzer , so if the DC signal cannot beep, it must be driven by a 2K~5K square wave.
An active buzzer is usually more expensive than a passive buzzer because it has an oscillating circuit.
2. Requirements for input signals
There is an oscillation circuit inside the active buzzer, but there is no inside the passive buzzer.
The working signal for an active buzzer is direct current , usually labeled VDC, VDD, etc.
The working signal of the passive buzzer is similar to alternating current , the working signal of the electromagnetic passive buzzer is a one-way square wave Vo-p, and the working signal of the piezoelectric passive buzzer is a two-way wave Vp-p.
3. The appearance
of the buzzer can be turned upside down.
If the circuit board is black, it means it is active.
If the board is green it is passive.
4. In the test mode
, adjust the multimeter to the ohm position.
If the resistance value is displayed, it is a passive buzzer.
If it makes a continuous sound, it is an active buzzer.
scene selection
General consumption or low requirements can choose active buzzer, DC drive sound.
If it is a high requirement, it is recommended to use a passive buzzer. Due to the simple structure and no other electronic components inside, the passive buzzer has a low failure rate and safe and reliable product performance. Different sound effects can be achieved by changing the frequency according to different needs.