big in value , or big in size ? 
lookielookie : http://www.diyaudio.com/forums/solid-state/161663-nem-ai-50-a.html#post2144101
observe value of L2
hop to 6moon article , read , study CRO photos
use PSUD to decide what's enough for your particular case
lookielookie : http://www.diyaudio.com/forums/solid-state/161663-nem-ai-50-a.html#post2144101
observe value of L2
hop to 6moon article , read , study CRO photos
use PSUD to decide what's enough for your particular case
I've been running a lot of PSUD simulations recently on choke input filters. Sometimes I get a warning that the rectifier reverse voltage has been exceeded. The voltage spike comes right at the zero crossing of the transformer voltage.
Usually the big peak in transformer current comes after the transformer voltage peak. (Current lags voltage in an inductor.) If you get the load current and capacitance just right, the current peak is very near the center of the voltage peak and looks like the current peak you normally see with capacitor input filters. No spikes. If you put a smallish capacitor on the rectifier side of the choke, you can increase the voltage between the choke input value and the cap input value. The problem becomes finding a cap that can withstand the ripple current.
Power factors (power out/power in) run about 60-65% with cap only or CLC filters. About 10% higher with LC filters.
Note: To get PSUD to spit out valid RMS numbers, run the simulation for 100mS to get 5 complete cycles at 50Hz or 6 complete cycles at 60Hz. Then you get pretty good numbers for the currents in all the components. There is also a feature that lets you calculate the transformers bulk impedance from the winding resistances and no load voltages.
I use a 2 second delay, but you can get a big voltage spike at turn on. Check what goes on with zero delay. I guess I'll be shopping for thermistors soon.
Usually the big peak in transformer current comes after the transformer voltage peak. (Current lags voltage in an inductor.) If you get the load current and capacitance just right, the current peak is very near the center of the voltage peak and looks like the current peak you normally see with capacitor input filters. No spikes. If you put a smallish capacitor on the rectifier side of the choke, you can increase the voltage between the choke input value and the cap input value. The problem becomes finding a cap that can withstand the ripple current.
Power factors (power out/power in) run about 60-65% with cap only or CLC filters. About 10% higher with LC filters.
Note: To get PSUD to spit out valid RMS numbers, run the simulation for 100mS to get 5 complete cycles at 50Hz or 6 complete cycles at 60Hz. Then you get pretty good numbers for the currents in all the components. There is also a feature that lets you calculate the transformers bulk impedance from the winding resistances and no load voltages.
I use a 2 second delay, but you can get a big voltage spike at turn on. Check what goes on with zero delay. I guess I'll be shopping for thermistors soon.
Thermistors specified by Mr. Pass in my circuit
Absolutely. Thermistors were specified by Mr. Pass in my PSU circuit.
Does PSUD simulate use of one CL 60 on each primary line lead to traf?
If so, how does this affect the peak voltage on rectifier(s)?
Thx,
-Joe
P.S. Loudthud:If you want I can send you a spare pair of CL60 I have lying around(PM me).
Absolutely. Thermistors were specified by Mr. Pass in my PSU circuit.
Does PSUD simulate use of one CL 60 on each primary line lead to traf?
If so, how does this affect the peak voltage on rectifier(s)?
Thx,
-Joe
P.S. Loudthud:If you want I can send you a spare pair of CL60 I have lying around(PM me).
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