What is A21 Bulb
An A21 bulb is a type of light bulb commonly used in domestic lighting applications. It is named A21 because it has a diameter of 21-eighths of an inch or approximately 2.625 inches. This bulb is characterized by its pear-shaped design, similar to the A19 bulb. The A21 bulb is typically used in various household fixtures such as table lamps, ceiling fans, and wall lights.
Maybe You Are Interested In
- Ceiling-mounted PIR occupancy sensor with dry-contact relay output
- 12/24VDC or 12/24VAC low-voltage supply
- COM, NO, and NC isolated relay contacts for EMS, HVAC, and building control inputs
- Low-voltage DC recessed ceiling-mounted microwave motion sensor switch
- 12 VDC / 24 VDC input with 10-30 VDC range
- 10A max work current with adjustable time delay, Lux threshold, and sensitivity
- Higher-load recessed ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 10A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Recessed ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 5A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Ceiling-mounted RZ037 PIR occupancy sensor dimmer for 220V power
- 3A maximum working current with 660W rated load
- LUX button controls light-sensor ON/OFF and user-set dimming brightness
- Ceiling-mounted RZ037 PIR occupancy sensor dimmer for 110V power
- 3A maximum working current with 330W rated load
- LUX button controls light-sensor ON/OFF and user-set dimming brightness
- Low-voltage DC ceiling-mounted microwave motion sensor switch
- 12 VDC / 24 VDC input with 10-30 VDC range
- 10A max work current with adjustable time delay, Lux threshold, and sensitivity
- Higher-load ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 10A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Ceiling-mounted microwave motion sensor switch
- 100-265 VAC line-voltage input, 5A model
- 5.8 GHz microwave sensing with adjustable time delay, Lux threshold, and sensitivity
- Low-voltage DC recessed ceiling mount PIR motion sensor switch
- 12 VDC / 24 VDC input with 10-30 VDC range
- Max work current 10A with adjustable time delay, Lux threshold, and sensitivity
- Higher-load recessed ceiling mount PIR motion sensor switch
- 100-265 VAC line-voltage input, 10A model
- 360-degree detection with adjustable time delay, Lux threshold, and sensitivity
- Recessed ceiling mount PIR motion sensor switch
- 100-265 VAC line-voltage input, 5A model
- 360-degree detection with adjustable time delay, Lux threshold, and sensitivity
- Wireless switch and receiver kit for indoor ON/OFF lighting control
- 100-230VAC, 50/60Hz receiver with 5A rated current
- CR2032-powered wireless switch with 2.4GHz communication
- Occupancy (Auto-ON/Auto-OFF)
- 12–24V DC (10–30VDC), up to 10A
- 360° coverage, 8–12 m diameter
- Time delay 15 s–30 min
- Light sensor Off/15/25/35 Lux
- High/Low sensitivity
- Auto-ON/Auto-OFF occupancy mode
- 100–265V AC, 10A (neutral required)
- 360° coverage; 8–12 m detection diameter
- Time delay 15 s–30 min; Lux OFF/15/25/35; Sensitivity High/Low
- Auto-ON/Auto-OFF occupancy mode
- 100–265V AC, 5A (neutral required)
- 360° coverage; 8–12 m detection diameter
- Time delay 15 s–30 min; Lux OFF/15/25/35; Sensitivity High/Low
- 100V-230VAC
- Transmission Distance: up to 20m
- Wireless motion sensor
- Hardwired control
- Voltage: 2x AAA Batteries / 5V DC (Micro USB)
- Day/Night Mode
- Time delay: 15min, 30min, 1h(default), 2h
- EU plug power adapter
- UK plug power adapter
One notable feature of the A21 bulb is its ability to produce strong and bright illumination. It is designed to accommodate higher wattages, resulting in a higher light output compared to smaller bulbs like the A19. This makes the A21 bulb suitable for rooms or areas that require ample lighting.
In terms of compatibility, the A21 bulb has a standard medium bulb base, allowing it to fit into most light fixtures. It offers a 360-degree beam angle, providing omnidirectional illumination. However, it is important to note that while the A21 bulb produces strong light, it does not fill the same amount of space with light as an A19 bulb.
Additionally, the larger size of the A21 bulb helps to dissipate heat more effectively, making it a suitable choice for LED lights. This is particularly important as excessive heat can damage the internal electronics of LED bulbs. However, it is worth considering that A21 bulbs tend to use more energy compared to smaller bulbs like the A19, so energy efficiency may be a consideration when choosing between the two.
Looking For Motion-Activated Energy-Saving Solutions?
Contact us for complete PIR motion sensors, motion-activated energy-saving products, motion sensor switches, and Occupancy/Vacancy commercial solutions.
