Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: jufelling on April 27, 2023, 03:57:26 AM

Title: Tentlab Mini Electronic Choke
Post by: jufelling on April 27, 2023, 03:57:26 AM

During the search for an european distributor of chokes to upgrade my Crack i stumbled upon the Tentlab Mini Electronic Choke.

https://www.hificollective.co.uk/components/tentlabs-mini-electronic-choke.html (https://www.hificollective.co.uk/components/tentlabs-mini-electronic-choke.html)

Manual: https://www.hificollective.co.uk/sites/default/files/tentlabs_mec_datasheet.pdf (https://www.hificollective.co.uk/sites/default/files/tentlabs_mec_datasheet.pdf)

The MEC-200 version seems to fit:

maximum DC output current: 200 mA
maximum input Vdc: 800 V
internal current limit: no
equivalent inductance: 10 H (same as the Triad C-7X)
maximum voltage drop @ Imax: 10 V
short circuit protection: No
protected for reverse connection: Yes
maximum heat production: 2,0 W
minimum capacity C1: 100 uF
optimal capacity C1: 220 uF

The only information missing is the resistance rating. From other threads I know this should be 270Ohm like the original resistor in that place.
Can the resistance be calculated with the information above or do I need to ask the distributor if he can measure it for me?
Is this little choke suitable at all?

Best
Julian

Title: Re: Tentlab Mini Electronic Choke
Post by: Paul Birkeland on April 27, 2023, 04:12:35 AM

There isn't a resistance value because that device isn't a resistor.  The voltage drop at 100mA is 10V, so perhaps a bit less at the current drawn by the Crack.  The device is optimized for a 100uF cap to follow it, so you'll have to follow their advice of using a scope and adding some series resistance to damp the switching resonance that will occur (you don't want to go from 220uF to 100uF in the Crack).

Title: Re: Tentlab Mini Electronic Choke
Post by: jufelling on April 27, 2023, 07:36:02 AM

Thank you for your fast and detailed response.
I‘ll go with the Triad.

But concerning the resistance - Why is the resistance mentioned here on the the page at Mouser:

https://eu.mouser.com/ProductDetail/Triad-Magnetics/C-7X?qs=%2FPiZ59IM4y3T0O8Zu9aP3g%3D%3D

Title: Re: Tentlab Mini Electronic Choke
Post by: Paul Birkeland on April 27, 2023, 01:31:57 PM

A choke is a coil of wire, and wire has a resistance.

Title: Re: Tentlab Mini Electronic Choke
Post by: jufelling on April 27, 2023, 10:22:53 PM

Okay I understand makes sense.
Thank you for answering even such trivial questions Paul.