LL1673 15H Lundahl Drossel Choke 15Henry 140mA max. 200mA
€124.80
Delivery time: ca. 4 - 8 weeks
Greater inductance than the 10 H model supports stronger B+ filtering
Parallel wiring provides 3.75 H at 280 mA recommended DC current in use
30 O per winding, 1.35 kg, C-core and 4 kV winding isolation overall
Lundahl LL1673/15H – C-core choke with greater filtering impedance
The Lundahl LL1673/15H is a dual-coil B+ filter choke for valve amplifiers. With both windings in series, it provides 15 H at 140 mA recommended DC and therefore greater inductance than the 10 H version.
For greater current, the two windings can be connected in phase and in parallel. This arrangement provides 3.75 H at 280 mA recommended DC.
Suitable applications
- Low-noise LC and CLC supplies for valve preamplifiers
- B+ filtering for driver stages and moderate power amplifiers
- 15 H series operation at up to 140 mA recommended DC
- 3.75 H parallel operation at up to 280 mA recommended DC
- Choke-input supplies after verifying minimum load and critical inductance
- Split common-mode filtering following the Lundahl diagram
Technical data
- Product type
- Dual-coil B+ filter choke
- Model version
- LL1673/15H
- Inductance with coils in series
- 15 H
- Recommended DC current in series
- 140 mA
- Saturation current in series
- Approx. 200 mA; not a recommended continuous current
- Inductance with coils in parallel
- 3.75 H
- Recommended DC current in parallel
- 280 mA
- Saturation current in parallel
- Approx. 400 mA; not a recommended continuous current
- DC resistance per winding
- Approx. 30 Ω
- Total resistance in series
- Approximately 60 Ω
- Equivalent resistance in parallel
- Approximately 15 Ω with equal current sharing
- Maximum ripple voltage in series
- 400 V RMS at 100 Hz and recommended DC current
- Maximum ripple voltage in parallel
- 200 V RMS at 100 Hz and recommended DC current
- Winding-to-winding dielectric test
- 4 kV AC
- Winding-to-core dielectric test
- 2 kV AC
- Core
- Lundahl audio C-core
- Winding insulation
- Insulation foil between individual copper layers
- Dimensions
- Approx. 95 × 75 × 50 mm
- Mounting pattern
- Approx. 35 × 75 mm with four M4 mounting points
- Weight
- Approx. 1.35 kg
- Country of origin
- Sweden
Winding connections
- First winding
- Pins 1 to 3, with the winding start at pin 1
- Second winding
- Pins 6 to 4, with the winding start at pin 6
- 15 H series connection
- Join pin 3 to pin 6 and use pins 1 and 4 as the terminals
- 3.75 H parallel connection
- Join pins 1 and 6 together and join pins 3 and 4 together with the correct phase
- Common-mode filtering
- An additional split series arrangement is shown in the manufacturer data sheet
Comparison with the 10 H version
- LL1673/15H in series
- 15 H at 140 mA, providing greater filtering impedance at lower recommended current
- LL1673/10H in series
- 10 H at 200 mA, providing greater current capability at lower inductance
- LL1673/15H in parallel
- 3.75 H at 280 mA
- LL1673/10H in parallel
- 2.5 H at 400 mA
Selection and application notes
At 140 mA, the approximately 60 Ω series connection produces a calculated drop of approximately 8.4 V and copper loss of 1.18 W. The 15 Ω parallel connection produces approximately 4.2 V drop at 280 mA.
The 15 H version is useful where filtering impedance and low residual hum take priority over the greater current capability of the 10 H version. The 200 mA saturation figure is not a recommended continuous current.
Choke-input operation requires calculation of minimum load, rectifier type and critical inductance. No-load voltage can rise substantially where the load is insufficient.
The choke can carry lethal voltage and requires complete touch-safe installation.
Questions about selection and use
Is the Lundahl LL1673/15H suitable for a CLC valve supply operating at up to 140 mA?
Yes, the Lundahl LL1673/15H is suitable in series connection for a correctly designed LC or CLC supply operating at up to 140 mA recommended DC. Voltage drop, start-up voltage and ripple must be considered.
Can the LL1673/15H be connected in parallel as a 3.75 H, 280 mA choke?
Yes, the LL1673/15H can operate with its windings connected in phase and in parallel as a 3.75 H choke for up to 280 mA recommended DC. Both windings must share current evenly.
Is the 15 H version suitable for a particularly low-noise preamplifier or driver supply?
Yes, the 15 H version is suitable for a correctly designed preamplifier or driver supply when its DC current remains below 140 mA and greater filtering impedance takes priority over additional current capability.
Note: All brand names mentioned, such as Marshall, Fender, etc., are registered trademarks of their respective owners and are used here for descriptive and compatibility purposes only.
Lundahl Transformers AB
SE-76150 Norrtälje
Email: order@lundahltransformers.com
The EU Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (2011/65/EU = "RoHS 2") aims to exclude certain hazardous substances from electrical and electronic equipment or to restrict the use of certain substances in electrical and electronic equipment. These include substances such as lead, mercury, cadmium, and chromium, as well as certain brominated flame retardants and plasticizers. These substances may only be used in electrical and electronic equipment up to a maximum concentration limit, unless exemptions in the annexes to the directive permit their use under certain conditions. This can reduce and eliminate harmful substances and improve the recycling of waste electrical and electronic equipment. To find out whether the component you purchased from us is permitted in your device, please refer to the current directive or the current law applicable to your country. If you are a manufacturer, please feel free to contact us to find out whether the component you require can be tested and approved according to the current directives. We would be happy to assist you.
Fact sheet on EU Directive 2011/65/EURestriction of the use of hazardous substances in electrical and electronic equipment (PDF, not accessible, 2 MB)
Source: IHK Mittelfranken
Tariff Number: 85043180000
Country of Origin: DE
Weight: 1,35 kg