LL1673 10H Lundahl Drossel Choke 10Henry 200mA max. 290mA
€124.80
Delivery time: ca. 1 - 3 days
Series wiring provides high filter impedance for LC and CLC supplies
Parallel wiring doubles recommended DC current capability to 400 mA
30 O per winding, 1.35 kg, C-core and 4 kV winding isolation overall
Lundahl LL1673/10H – configurable C-core choke for high-current valve supplies
The Lundahl LL1673/10H is a dual-coil B+ filter choke for valve-amplifier power supplies. With both windings in series, it provides 10 H at 200 mA recommended DC.
Connecting the windings in phase and in parallel provides 2.5 H at 400 mA recommended DC. The same choke can therefore prioritise either greater filtering impedance or greater current capability.
Suitable applications
- LC and CLC filtering in valve-amplifier power supplies
- B+ supplies for mono and stereo push-pull amplifiers
- 10 H series operation at up to 200 mA recommended DC
- 2.5 H parallel operation at up to 400 mA recommended DC
- Choke-input supplies after calculation of minimum load and critical inductance
- Split common-mode filtering following the Lundahl connection diagram
Technical data
- Product type
- Dual-coil B+ filter choke
- Model version
- LL1673/10H
- Inductance with coils in series
- 10 H
- Recommended DC current in series
- 200 mA
- Saturation current in series
- Approx. 290 mA; not a recommended continuous current
- Inductance with coils in parallel
- 2.5 H
- Recommended DC current in parallel
- 400 mA
- Saturation current in parallel
- Approx. 580 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
- Series connection
- Join pin 3 to pin 6 and use pins 1 and 4 as the terminals
- Parallel connection
- Join pins 1 and 6 together and join pins 3 and 4 together with the correct phase
- Common-mode filtering
- Lundahl also shows a split series connection intended to improve common-mode rejection
Selection and application notes
At 200 mA, the approximately 60 Ω series connection produces a calculated drop of approximately 12 V and copper loss of 2.4 W. At 400 mA, the approximately 15 Ω parallel connection produces a 6 V drop and the same 2.4 W loss.
The greater inductance of the series connection improves filtering impedance, while the parallel connection provides greater current capability. The saturation current is not a recommended continuous load.
Choke-input operation requires calculation of the rectifier, critical inductance, minimum load and possible no-load voltage. Insufficient minimum load can cause B+ to rise substantially.
Lethal voltage and stored energy may be present at the choke. Installation and wiring require complete touch protection.
Questions about selection and use
Is the Lundahl LL1673/10H suitable for a CLC valve supply operating at up to 200 mA?
Yes, the Lundahl LL1673/10H is suitable in series connection for a correctly designed LC or CLC supply operating at up to 200 mA recommended DC. Voltage drop, ripple and start-up conditions must suit the circuit.
Can the LL1673/10H be connected in parallel as a 2.5 H, 400 mA choke?
Yes, the LL1673/10H can operate with its windings connected in phase and in parallel as a 2.5 H choke for up to 400 mA recommended DC. Both windings must share current evenly.
Is the LL1673/10H suitable for a choke-input power supply?
Yes, the LL1673/10H can be used in a correctly calculated choke-input supply. Critical inductance, continuous minimum load, rectifier current and no-load voltage must be verified first.
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: 85043180
Country of Origin: SE
Weight: 1,35 kg