I figured as much. I will check the Hammond datasheets even closer, but I can understand why you chose to have them custom made. But since they are swinging, I gather it is best not to get one with current capability within the load range, or at least with low enough current capability to ensure thr load is never below the critical level of inductance. Not sure I saw an obvious candidate ok that least that also had low Rdc, but need to study closer and model a bit.
what's written on mine as "2A" is more like nominal current...... far from saturation figure
now, with A Class amps many things are simple enough - do not overthink that much
CLC cell made of 33mF-5mH-33mF ....... or 22mF-5mH-22mF is more than good for Iq between 1A3 and 2A, speaking from experience
now, with A Class amps many things are simple enough - do not overthink that much
CLC cell made of 33mF-5mH-33mF ....... or 22mF-5mH-22mF is more than good for Iq between 1A3 and 2A, speaking from experience
The minimum inductance for a choke input power supply is approximately:
L = V/I for 60Hz
L=1.2V/I for 50Hz
where L=inductance Lin Henries, V=output voltage in volts, I=minimum output current in mA
Some information here:
https://www.qsl.net/i0jx/supply.html
Google is your friend - more information to be found.
L = V/I for 60Hz
L=1.2V/I for 50Hz
where L=inductance Lin Henries, V=output voltage in volts, I=minimum output current in mA
Some information here:
https://www.qsl.net/i0jx/supply.html
Google is your friend - more information to be found.
I didn't understood you're asking specifically for choke input arrangement
anyhow, what Ben said, math is welcome and - anything further must be conducted strictly in firm context - which exact project/load/amplifier
Choke input power filters were an old solution to a problem that we don’t have anymore. Thanks to modern manufacturing, we have large value capacitors readily available at reasonable cost. CRC filtering is much easier to work with. CLC or CLCC will eliminate hum and provide a smooth inky background for your music. Pay attention to the Q factor of your chokes.
choke input filtering is still "superior" to anything else, if speaking of xformer and rectifier loading
besides, there is something wakoo about inductive energy storage, comparing to capacitive one ....... Mighty Moi not equipped (with anything else than extraordinary capability for BS) to explain how and why
though, applicable to narrow range of constructions, sort of permanent loading is necessity...... and if biasing/Iq rise after powering up is not immediate ( and rarely is) one must account that for caps voltage
I was thinking to include choke input filter in my ( ever) upcoming build of Singing Bush, but I'm not sure that I have that sort of additional time on my hands
next life, certainly
besides, there is something wakoo about inductive energy storage, comparing to capacitive one ....... Mighty Moi not equipped (with anything else than extraordinary capability for BS) to explain how and why
though, applicable to narrow range of constructions, sort of permanent loading is necessity...... and if biasing/Iq rise after powering up is not immediate ( and rarely is) one must account that for caps voltage
I was thinking to include choke input filter in my ( ever) upcoming build of Singing Bush, but I'm not sure that I have that sort of additional time on my hands
next life, certainly
Well that should be a fun experiment.
I had considered choke input on a build that is still in progress, the new Stasis FE and OS. The tricky part is designing for the range of current that the chokes will be required to pass. The class A amps that we like to build here take a while to start up and reach thermal eq. Chokes are not quite as linear as the other parts we are used to. The big iron laminations start to saturate soon after they reach their rated current. Their inductance actually goes up a little when they are well below rated current. (At least this is true for the Hammond chokes)
Handling the Q factor will be important to avoid ringing in the power supply. This may be done by adding a small value series resistance (~ 0.2 Ohm), or a larger value parallel resistance (~ 2.2 Ohm). I recommend building a 1A current source and using that to help measure the actual DC resistance of your chokes. I would also recommend installing a small film capacitor, around 2.2uF to 10uF, in front of that first choke. It will help absorb back-EMF spikes. The initial choke resistance upon turn-on can be quite impressive, before the magnetic field has time to develop.
I had considered choke input on a build that is still in progress, the new Stasis FE and OS. The tricky part is designing for the range of current that the chokes will be required to pass. The class A amps that we like to build here take a while to start up and reach thermal eq. Chokes are not quite as linear as the other parts we are used to. The big iron laminations start to saturate soon after they reach their rated current. Their inductance actually goes up a little when they are well below rated current. (At least this is true for the Hammond chokes)
Handling the Q factor will be important to avoid ringing in the power supply. This may be done by adding a small value series resistance (~ 0.2 Ohm), or a larger value parallel resistance (~ 2.2 Ohm). I recommend building a 1A current source and using that to help measure the actual DC resistance of your chokes. I would also recommend installing a small film capacitor, around 2.2uF to 10uF, in front of that first choke. It will help absorb back-EMF spikes. The initial choke resistance upon turn-on can be quite impressive, before the magnetic field has time to develop.
When I built single ended Class A tube electronics all of my power supplies were choke input. Tube circuits were more suited to choke input as they were high voltage and low current. The better regulation of choke input allowed the use of lower value high voltage capacitors.
All of my solid state amplifiers have capacitor input power supplies.
With some unused chassis parts, I now have an outboard +/- 24 VDC SMPS! Another mechanical-only project complete. 
I‘ve had this MicroAudio SMPS idle for a while and have only used it recently to test new builds. Now it’s all closed up and safe* for more testing of builds or putting in an active system. There are additional 2 x 10 mF caps per output rail, using the MicroAudio cap bank I originally got with the SMPS. Powercon knockoff connectors and Wago-like splitters for two outputs. Still need to install a PE connector from PS chassis to amp chassis. First power on went fine, so it’s powering my 2SK1530 / 2SJ201 F5 and my test speakers.
Silent background and sounding beautiful. This pleases me.
I‘ve had this MicroAudio SMPS idle for a while and have only used it recently to test new builds. Now it’s all closed up and safe* for more testing of builds or putting in an active system. There are additional 2 x 10 mF caps per output rail, using the MicroAudio cap bank I originally got with the SMPS. Powercon knockoff connectors and Wago-like splitters for two outputs. Still need to install a PE connector from PS chassis to amp chassis. First power on went fine, so it’s powering my 2SK1530 / 2SJ201 F5 and my test speakers.
Silent background and sounding beautiful. This pleases me.
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