Tentlabs Electronic Choke

[Cantplay]

Anyone familiar with this?

http://www.tentlabs.com/Components/Tube ... UAL-UK.pdf

John

[gingertube]

John,
It is a gyrator. That is, it uses a MOSFET with capacitive feedback around it to make it behave like a choke - except of-course that it cannot store energy in a magnetic core. It does however exhibit the inductance of a choke.

There is some stuff around the internet (not too difficult to find) on this including a couple of post to other forums I have made. Those posts usually had most of the more useful links to technical stuff.

I have a couple of the bigger E-Choke PCB modules in some tube HIFI power amps I built. They (the big modules) have a link on the board to switch between full gyrator mode and a mode which is reduced gyrator function but with added capacitance multiplier.

Cheers,
Ian

[Structo]

Interesting.

Does anybody in the states sell them?

Tentlab's price works out to be about $38 for the MEC-100

[John_P_WI]

Ken Moon has a nice example of a gyrator here:

https://tubeamparchive.com/viewtopic.ph ... ght=filter

He has another thread that I remember too, just could not put my finger on it quickly.

[gingertube]

John_W_PI,
That circuit is a Capacitance Multiplier.

Here is something a quick search turned up on Gyrators.
http://web12491.serv4.spacequadrat.de/h ... yrator.pdf


Cheers,
Ian

[EtherealWidow]

I think Ricky Martin has a better example of a gyrator.

[John_P_WI]

Cheers Ian,

Thank you for setting things straight. Thank you again for your knowledge. Sure do miss your posts over at the now defunct powerscaling.com

John

[gingertube]

And here is the big brother of those, the E-Choke

With the link out it is a gyrator, with the link in the gyrator action is reduced by a factor of 10 (by capacitor divider action) but capacitance multiplication function is added.

Cheers,
Ian

[JazzGuitarGimp]

Merlin also discusses the gyrator circuit in his power supplies for tube amps book.