I am not familiar with this setup with a choke before the bridge... What's its purpose? I would think that a RC / LC filter (after the bridge) would filter out RF/HF anyway no?
Sorry, i do not find the time to explain the "choke before the bridges" thing at the moment. Frans did the original circuit and it must be somewhere on the thread.
This is the correct way to use a common mode choke.
To use a choke behind the bridges in a pi filter is fine too. The Telema is high in value enough to be "raped" to do that job. It is better though to use chokes that are optimized for this duty and they are usually bigger in value and size. The Lundahl i use in this sense behind the bridges and between the caps. One glance at the picture makes that obvious. The only "speciality" of my pre regulator is that i have setup the Lundahl as a common mode choke too.
This is the correct way to use a common mode choke.
To use a choke behind the bridges in a pi filter is fine too. The Telema is high in value enough to be "raped" to do that job. It is better though to use chokes that are optimized for this duty and they are usually bigger in value and size. The Lundahl i use in this sense behind the bridges and between the caps. One glance at the picture makes that obvious. The only "speciality" of my pre regulator is that i have setup the Lundahl as a common mode choke too.
Here is the spec sheet of the Lundahl that also shows how to connect for common mode :http://www.lundahl.se/pdf/2733.pdf
So in this case you actually mimic the effect of a four pole cap 🙂
CAP + common mode choke + CAP
CAP + common mode choke + CAP
I think that the 4 pole caps work a bit different.
The common mode coil works in such a way that noise that is common in both phases cancels. The rest of the circuit is a conventional CLC filter. It works like a low pass, suppressing high frequency artifacts. Here 50Hz is a high frequency, so the low pass is set very low.
The common mode coil works in such a way that noise that is common in both phases cancels. The rest of the circuit is a conventional CLC filter. It works like a low pass, suppressing high frequency artifacts. Here 50Hz is a high frequency, so the low pass is set very low.
These are the most important/relevant messages regarding PSU and Pre-Reg.
Mpp - Post 4375 PSU-pre-regulator
Mpp - Post 4610 V2 Schemas UPS and Amp
Mpp - Post 6506 CCS fine-tuning
Mpp - Post 6462 PSU with my notes
Mpp - Post 6809 Do not try to feed the CVS of the CCS of the shunt with a regulated power supply
Have a look at these and the following messages (#4375 for the pre-reg where the chokes are used to get rid of net/transformer HF).
Hi Joachim
Could you point another supply source than Reichelt ?
If we preserve similar specs part as CAF 0.6-100, would it be Ok ?
100mH is a min or a max ? Same thing about 0.6A value.
Regards
Phil
Could you point another supply source than Reichelt ?
If we preserve similar specs part as CAF 0.6-100, would it be Ok ?
100mH is a min or a max ? Same thing about 0.6A value.
Regards
Phil
Looking at the Jensen pdf https://audio.jensencapacitors.com/public/dokumenter/4pole.pdf I got the idea that there are two common mode chokes, one before and another after the capacitor.
Attachments
Holger, the Lundahl spec sheet shows the option to connect common mode in a CLC filter.
I think Onkyo did something like that even in power amps.
I think Onkyo did something like that even in power amps.
Korben, you can find Panasonic common mode coils at Mouser and Digikey. Some say they are even better then the Talemas.
Another idea. The Telema could be modified to put the two coils in series so that they form a conventional coil with 200mH. Be careful though to connect them in such a way that they do not cancel.