The MEIDI HND-4020 3KHz Piezo Electronic Alarm is an electronic alarm unit designed for audible warning and alert applications. It uses a piezoelectric transducer driven by an external square-wave or PWM signal, allowing system designers to control tone frequency and pattern.
The HND-4020 resonates at 3000±500Hz and produces Min. 89dB sound pressure at 3Vp-p, 3kHz, 50% duty, measured at 30cm. The wide 1~25Vp-p operating range supports various driver circuit designs. With a capacitance of 30000±30%pF at 1kHz and a black PPO housing, this electronic alarm suits industrial, security, and process-control alert systems.
External drive flexibility — accepts PWM or square-wave drive for programmable tone output
3000Hz resonant frequency — factory-tuned with ±500Hz tolerance
Wide voltage range — 1~25Vp-p operating range supports diverse driver circuits
Low current consumption — Max. 5mA at 3Vp-p, 3kHz, 50% duty
PPO housing — black PPO material for thermal and mechanical durability
| Parameter | Value | Test Conditions |
| Product Type | Electronic Alarm | — |
| Rated Voltage | 3 Vp-p | Per test conditions |
| Operating Voltage | 1~25 Vp-p | Drive signal range |
| Resonant Frequency | 3000 ±500 Hz | — |
| Sound Pressure Level | Min. 89 dB | 3Vp-p, 3kHz, 50% duty, 30cm |
| Rated Current | Max. 5 mA | 3Vp-p, 3kHz, 50% duty |
| Capacitance | 30000 ±30% pF | At 1kHz |
| Operating Temperature | -20℃ ~ +70℃ | Continuous |
| Storage Temperature | -30℃ ~ +80℃ | Non-operating |
| External Dimensions | Φ39.5 × 26 mm | Body only, per dimension drawing |
| Mounting Hole Spacing | 18 mm | Per dimension drawing |
| Net Weight | Approx 15 g | — |
| Housing Material | PPO | Black |
| Environmental Compliance | RoHS | — |
External drive alarm systems — equipment with a microcontroller or driver IC providing PWM or square-wave output
Industrial process alerts — fault and hazard warnings in control systems
Security panels — intrusion and status alarms driven by external control signals
Programmable alert systems — frequency modulation enables multi-tone and variable pattern output
General electronic equipment — status tones, error notifications, and operator feedback
| Design Requirement | HND-4020 Advantage |
| Programmable tone output | External PWM drive enables variable frequency and patterns |
| Wide voltage compatibility | 1~25Vp-p operating range accommodates various driver designs |
| Low current draw | Max. 5mA at rated test conditions |
| Panel mounting | Φ39.5mm housing with mounting holes for chassis installation |
| Drive circuit matching | 30000pF nominal capacitance for standard piezo driver matching |
MEIDI manufactures the HND-4020 electronic alarm under controlled production processes. Each production lot undergoes:
Frequency verification — resonant frequency test at 3000±500Hz
SPL verification — sound pressure verification at 3Vp-p, 3kHz, 50% duty, 30cm
Current consumption test — Max. 5mA check under rated test conditions
Dimensional inspection — Φ39.5×26mm body and mounting-hole layout check
Reliability testing — including 96-hour ordinary temperature life test, +80℃ high-temperature storage, -30℃ low-temperature storage, 48-hour humidity exposure at +40℃/90–95%RH, 10-cycle temperature shock (+70℃↔-20℃), 1.2m drop test, and multi-axis mechanical vibration
Products are manufactured with RoHS-compliant materials. Contact MEIDI for detailed quality documentation and test reports.
1. Does the HND-4020 require an external oscillator or PWM signal?
Yes. The HND-4020 requires an external AC or PWM signal at or near its resonant frequency of 3000Hz. DC voltage alone will not produce audible output because the piezoelectric element requires polarity reversal to mechanically flex and generate sound pressure.
2. What driving voltage and frequency are recommended for the HND-4020?
The source specification lists test conditions of 3Vp-p, 3kHz, 50% duty square wave. The operating voltage range is 1~25Vp-p. For rated sound output, drive at 3Vp-p near the resonant frequency.
3. Why is the SPL measured at 30cm instead of 10cm?
The source specification lists Min. 89dB at 30cm under rated test conditions. This measuring distance is part of the defined test condition and should be used when comparing acoustic output.
4. What is the capacitance of the HND-4020 and why does it matter?
The nominal capacitance is 30000±30%pF at 1kHz. This capacitive load determines the current required from the driver circuit. Verify the driver can source sufficient current at your switching frequency and voltage.
5. What are the mounting dimensions of the HND-4020?
The dimension drawing shows a Φ39.5mm diameter body with 26mm total height and mounting holes spaced 18mm apart. Contact MEIDI for the official mechanical drawing.
For technical datasheets, drive circuit application notes, frequency response data, or OEM configuration discussion, contact MEIDI. Product specifications and qualification documentation are available under mutual NDA.
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No.6, Wenlin Road, Chenbao Town, Xinghua City, Jiangsu Province, China
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