Low Voltage LED Filament Bulbs
DC and AC/DC filament bulb solutions for battery, solar, RV, marine, hospitality and other low-voltage lighting systems. Select the electrical architecture first, then confirm shape, base, wattage, dimmer and transformer compatibility.
Choose the electrical solution before choosing the bulb shape
A low-voltage DC bulb and a low-voltage AC/DC bulb are not the same product with reversed polarity. Their driver architecture, acceptable power source, voltage tolerance, flicker behavior and dimming compatibility are different. HongYu Bulb offers three established configurations for project matching.
DC resistor solution
For constant-voltage DC supplies or batteries. Available at 3.7V, 5V, 12V and 24V. It has a simple circuit and no AC rectification, but power changes more noticeably when the supply voltage moves away from nominal.
IC-A buck AC/DC solution
For compatible 12V or 24V AC/DC supplies. The circuit combines an IC, bridge rectifier, capacitor, resistor and filament. It supports low-flicker operation and dimming with a limited, tested set of transformers and dimmers.
IC-B boost AC/DC solution
For compatible 12V or 24V AC/DC supplies where broader control matching is required. It also supports single-voltage designs with about +/-3V tolerance or a 12-24V wide-voltage project configuration.
Key product range
Product gallery
3.7V / 5V DC
A60-3W-C-3.7V-DC
Clear
G45-3W-C-3.7V-DC
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C35-3W-C-3.7V-DC
Clear
A60-3W-C-5V-DC
Clear
G45-3W-C-5V-DC
Clear
C35-3W-C-5V-DC
Clear
12V / 24V DC
A60-3.5W-C-12V-DC
Clear
A60-6W-C-12V-DC
Clear
G45-3W-C-12V-DC
Clear
C35-3W-C-12V-DC
Clear
A60-3.5W-C-24V-DC
Clear
A60-6W-C-24V-DC
Clear
G45-3W-C-24V-DC
Clear
C35-3W-C-24V-DC
Clear
12V / 24V AC/DC - IC-A
A60-3.5W-C-12V-AC/DC-A
Clear
A60-6W-C-12V-AC/DC-A
Clear
G45-3.5W-C-12V-AC/DC-A
Clear
C35-3.5W-C-12V-AC/DC-A
Clear
A60-3.5W-C-24V-AC/DC-A
Clear
A60-6W-C-24V-AC/DC-A
Clear
G45-3.5W-C-24V-AC/DC-A
Clear
C35-3.5W-C-24V-AC/DC-A
Clear
12V / 24V AC/DC - IC-B
A60-3.5W-C-12V-AC/DC-B
Clear
A60-6W-C-12V-AC/DC-B
Clear
G45-3.5W-C-12V-AC/DC-B
Clear
C35-3.5W-C-12V-AC/DC-B
Clear
A60-3.5W-C-24V-AC/DC-B
Clear
A60-6W-C-24V-AC/DC-B
Clear
G45-3.5W-C-24V-AC/DC-B
Clear
C35-3.5W-C-24V-AC/DC-B
Clear
12V AC/DC specialty finishes
A60-3.5W-W-12V-AC/DC
Porcelain
G80-6W-W-12V-AC/DC
Porcelain
ST64-4W-G-12V-AC/DC
Gold
ST64-4W-S-12V-AC/DC
Smoky
Full specifications
| Item No. | Size | Voltage | Lamp Base | Watts | CCT | Ra | Lumen | Finish |
|---|---|---|---|---|---|---|---|---|
| 3.7V / 5V DC | ||||||||
| A60-3W-C-3.7V-DC | 60 x 105 mm | 3.7V DC | E26 / E27 / B22 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| G45-3W-C-3.7V-DC | 45 x 78 mm | 3.7V DC | E26 / E27 / E12 / E14 / B15 / E17 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| C35-3W-C-3.7V-DC | 35 x 98 mm | 3.7V DC | E12 / E14 / B15 / E17 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| A60-3W-C-5V-DC | 60 x 105 mm | 5V DC | E26 / E27 / B22 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| G45-3W-C-5V-DC | 45 x 78 mm | 5V DC | E26 / E27 / E12 / E14 / B15 / E17 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| C35-3W-C-5V-DC | 35 x 98 mm | 5V DC | E12 / E14 / B15 / E17 | 3W | 2700K | 80 / 90 / 95 | 280 lm | Clear |
| 12V / 24V DC | ||||||||
| A60-3.5W-C-12V-DC | 60 x 105 mm | 12V DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-12V-DC | 60 x 105 mm | 12V DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3W-C-12V-DC | 45 x 78 mm | 12V DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3W-C-12V-DC | 35 x 98 mm | 12V DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-3.5W-C-24V-DC | 60 x 105 mm | 24V DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-24V-DC | 60 x 105 mm | 24V DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3W-C-24V-DC | 45 x 78 mm | 24V DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3W-C-24V-DC | 35 x 98 mm | 24V DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| 12V / 24V AC/DC - IC-A | ||||||||
| A60-3.5W-C-12V-AC/DC-A | 60 x 105 mm | 12V AC/DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-12V-AC/DC-A | 60 x 105 mm | 12V AC/DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3.5W-C-12V-AC/DC-A | 45 x 78 mm | 12V AC/DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3.5W-C-12V-AC/DC-A | 35 x 98 mm | 12V AC/DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-3.5W-C-24V-AC/DC-A | 60 x 105 mm | 24V AC/DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-24V-AC/DC-A | 60 x 105 mm | 24V AC/DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3.5W-C-24V-AC/DC-A | 45 x 78 mm | 24V AC/DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3.5W-C-24V-AC/DC-A | 35 x 98 mm | 24V AC/DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| 12V / 24V AC/DC - IC-B | ||||||||
| A60-3.5W-C-12V-AC/DC-B | 60 x 105 mm | 12V AC/DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-12V-AC/DC-B | 60 x 105 mm | 12V AC/DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3.5W-C-12V-AC/DC-B | 45 x 78 mm | 12V AC/DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3.5W-C-12V-AC/DC-B | 35 x 98 mm | 12V AC/DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-3.5W-C-24V-AC/DC-B | 60 x 105 mm | 24V AC/DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| A60-6W-C-24V-AC/DC-B | 60 x 105 mm | 24V AC/DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 600 lm | Clear |
| G45-3.5W-C-24V-AC/DC-B | 45 x 78 mm | 24V AC/DC | E26 / E27 / E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| C35-3.5W-C-24V-AC/DC-B | 35 x 98 mm | 24V AC/DC | E12 / E14 / B15 / E17 | 3.5W | 2700K | 80 / 90 / 95 | 300 lm | Clear |
| 12V AC/DC specialty finishes | ||||||||
| A60-3.5W-W-12V-AC/DC | 60 x 105 mm | 12V AC/DC | E26 / E27 / B22 | 3.5W | 2700K | 80 / 90 / 95 | 250 lm | Porcelain |
| G80-6W-W-12V-AC/DC | 80 x 120 mm | 12V AC/DC | E26 / E27 / B22 | 6W | 2700K | 80 / 90 / 95 | 490 lm | Porcelain |
| ST64-4W-G-12V-AC/DC | 64 x 140 mm | 12V AC/DC | E26 / E27 / B22 | 4W | 2000K | 80 / 90 / 95 | 200 lm | Gold |
| ST64-4W-S-12V-AC/DC | 64 x 140 mm | 12V AC/DC | E26 / E27 / B22 | 4W | 2200K | 80 / 90 / 95 | 100 lm | Smoky |
Typical applications
- Battery-powered and portable decorative lighting
- Solar and off-grid constant-voltage systems
- RV, caravan and marine interior fixtures
- Low-voltage hospitality and architectural installations
- Visible-bulb decorative fixtures requiring warm filament appearance
OEM and engineering options
- DC, IC-A or IC-B driver architecture
- Filament lengths from 26 mm to 300 mm, subject to bulb structure
- A60, C35, G45, G80 and ST64 shapes
- E12, E14, B15, E17, E26, E27 and B22 bases
- Clear, porcelain, gold and smoky finishes
- CCT, CRI, logo and packaging customization
Compliance and sourcing notes
Available project support can include LVD, EMC, RoHS and FCC-related documentation, depending on the final driver configuration and destination market. BSCI concerns factory social-compliance assessment rather than product electrical certification. A two-year warranty is available for confirmed configurations. Ask us to verify enclosed-fixture suitability against the final wattage, ambient temperature and fixture volume.
For mains-voltage filament bulbs, browse our EU standard LED filament bulb range. For compact capsule and spotlight formats, see G4, G9 and spotlight lamps.
Dimming & Control System Compatibility
Low-voltage LED filament bulbs do not normally communicate directly with DALI, DMX512, KNX or Casambi. These systems send commands to a driver, decoder or dimming actuator. The bulb must match the electrical output of that equipment: for example, 12V or 24V constant-voltage DC with pulse-width modulation (PWM). Other equipment may deliver steady DC or a dimmed AC/DC waveform, which needs a different compatibility assessment.
One control system, two separate paths
- Control signal
- DALI / DMX512 / KNX / Casambi → matching PWM controller or decoder
- Power to bulbs
- 24V DC power supply → PWM controller or decoder → 24V PWM output → selected HongYu Bulb 24V DC filament bulbs
This example uses a separate power supply. A driver with an integrated power supply follows its own input and wiring requirements. The control bus is not the bulb power connection. For a 12V project, use a matching 12V supply, output stage and bulb configuration.
Multiple bulbs connected to the same constant-voltage dimming channel operate as one lighting group. Connect compatible bulbs in parallel within the channel, power-supply and wiring limits. They receive the same dimming command; the bulbs do not each acquire a DALI or DMX address.
For Lamp 1 at 30%, Lamp 2 at 70% and Lamp 3 at 100%, the simple PWM architecture needs three independently controlled output channels, or another architecture that provides individual control. These percentages illustrate separate commands, not guaranteed measured light output.
DALI
Compatible with selected DALI constant-voltage dimming systems through a suitable DALI LED driver/controller. This applies to the specific bulb and control-gear combination after sample validation, not to every DALI device.
DALI controller → DALI bus → DALI CV driver or dimmer → matching 12V / 24V PWM output → bulb group.
DALI Alliance lists a 24V constant-voltage PWM driver, confirming this output architecture exists.[1] Its listing applies to that driver; it does not certify the connected bulbs. Addressing belongs to the control gear, with channel behavior depending on its configuration.
DMX512
A suitable constant-voltage DMX decoder converts control data into PWM output.[2] For single-colour filament bulbs, one independent PWM output controls one independently dimmable bulb group.
DMX console → DMX512 → CV DMX decoder → matching 12V / 24V PWM output → bulb group.
This is a useful starting point for large chandeliers, exhibitions, events and decorative installations. Individual bulb control needs separate outputs. DMX address allocation depends on the decoder mode and resolution; one physical PWM output does not always equal one DMX data slot.
KNX
Route A: KNX → KNX constant-voltage PWM LED dimmer → matching 12V / 24V PWM output → bulb group.[3]
Route B: KNX → KNX-to-DALI gateway → DALI CV driver or dimmer → matching PWM output → bulb group.[4]
The bulb does not need a KNX interface in either arrangement. Select the output hardware and independently controlled groups to match the project.
Casambi and other control systems
Casambi-enabled constant-voltage PWM dimmers can sit between a DC power supply and a compatible LED load.[5]
Casambi app or network → Casambi PWM dimmer → matching 12V / 24V PWM output → bulb group.
For 0/1-10V or other control interfaces, the final driver output still determines bulb suitability. A familiar protocol name alone does not establish compatibility.
Choose the bulb circuit for the output stage
For constant-voltage PWM projects, the 12V or 24V DC resistor configuration is the starting point for evaluation. Confirm PWM response on the exact model. An AC/DC rating or a dimmable label does not establish PWM suitability for IC-A or IC-B versions: rectifiers, capacitors and internal driver behavior can affect minimum output, start-up, off-state glow and the current seen by the controller.
Validate the complete system before production
- Equipment: supply or transformer model, controller/decoder model, nominal voltage, output waveform, PWM frequency and dimming settings.
- Loading: exact bulb model, bulbs per channel, total current, start-up current, controller derating, cable length and voltage drop.
- Dimming: lowest stable and repeatable level, direct start at low levels, smooth fades, off-state glow, visible flicker and camera banding.
- Reliability: full-output temperature in the intended fixture, repeated switching, and recovery after power interruption.
Record the accepted dimming range and test conditions for the approved combination. A proposed test matrix is not a completed test report, and no universal PWM frequency range or 0-100% dimming performance is claimed for this collection.
Send the equipment datasheets and channel plan to HongYu Bulb for circuit selection and a project sample test plan.
FAQ
What is the difference between DC and AC/DC low-voltage bulbs?
DC-only bulbs require a constant-voltage DC supply or battery. AC/DC bulbs use a driver and bridge circuit designed for compatible low-voltage AC or DC supplies. Do not treat the two versions as interchangeable.
Can a 12V DC bulb run on a 12V AC transformer?
Only a model specified as 12V AC/DC should be used on a 12V AC transformer. A DC-only bulb is intended for a constant-voltage DC supply.
Are these bulbs dimmable?
Dimmable configurations are available, but compatibility depends on the transformer, dimmer and lamp combination. Test samples with the intended control gear before production approval.
Which shapes and bases are available?
The listed range covers A60, C35, G45, G80 and ST64 with E12, E14, B15, E17, E26, E27 and B22 base options depending on model and wattage.
Do these bulbs connect directly to DALI, DMX512, KNX or Casambi?
No. The selected bulb operates from the electrical output of a suitable driver, decoder or dimmer. For constant-voltage PWM systems, match the 12V or 24V DC bulb configuration to the actual output and validate the complete combination. The bulb itself does not have a DALI, DMX or KNX address.
Can bulbs on the same PWM output dim independently?
No. Multiple bulbs connected to the same constant-voltage dimming channel operate as one lighting group. Individual control requires separate independently controlled output channels or another architecture that supports individual control.
Send us your power-supply and dimmer details
We will match the driver solution, voltage, bulb shape, base and sample plan for your project.
Control system references
These sources describe control equipment and system architectures. They are not test reports or endorsements of compatibility with HongYu Bulb products.