Power supply schematic
Hi
Where can I find the schematic for the F5 power supply?
I've seen folks make reference to it here on this thread but the F5 article that I downloaded from Mr pass's site does not show the PS schem.
I also looked to see if there was a Service Manual for the F5 with no luck..
I would just feel more comfortable using the proper PS schem..
Thanks for the help
Sean
Hi
Where can I find the schematic for the F5 power supply?
I've seen folks make reference to it here on this thread but the F5 article that I downloaded from Mr pass's site does not show the PS schem.
I also looked to see if there was a Service Manual for the F5 with no luck..
I would just feel more comfortable using the proper PS schem..
Thanks for the help
Sean
AndrewT said:
Hi,
no way. The voltages aren't even similar.
A 160VA 24+24Vac transformer has a maximum continuous AC current output of 3.33A into a resistive load.
When fed into a capacitive input filter the maximum continuous DC current draw is reduced to ~1.67A.
This continuous current draw will make the transformer run at maximum temperature. It will be HOT inside.
The maximum continuous DC current is recommended @ ~50% of rating.
This reduces your 160VA to just 800mA of continuous DC output current.
What is the quiescent current of a single channel F5?
Edit,
divide by two error corrected.
AndrewT said:
Shucks, I guess I'll have to get a bigger transformer.
What should I be looking for then? besides 2x 18vac?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=122-620
Is 250va enough? The price is right, and it comes with a mounting kit.
merlin2069er said:
Looks like a good trany, buuuuuut! Great googly moogly, I guess you've missed the tranny in one of these F5 threads about the supplier right in your back yard. Antek ..........
....Antek of this group buy and asked if there might be any preferential pricing available for his AN-4218 torroid. That is 2 x 18, 400 VA. John replied: "I can offer the individual (transformers)... at $37 each for your group. Please use this discount code GN8128 "shipping not included" http://www.antekinc.com/
This is the baby to use and it's larger (VA) and cheaper. Great service too.
Antek Trannies
I concur with Ichiban - John's Antek toroids are beautiful and half the price of a Plitron. His service is excellent also.
Someone else on the forum is building a test set-up to "listen" for transformer sonic differences, but I think the Antek's will work just fine. Cap, resistor and rectifier (standard vs. soft-recovery) selections will probably have a greater impact, IMHO. (BTW, Papa is not overly enamored with soft recovery rectifiers, even though they have become pretty cheap to use.....)
I concur with Ichiban - John's Antek toroids are beautiful and half the price of a Plitron. His service is excellent also.
Someone else on the forum is building a test set-up to "listen" for transformer sonic differences, but I think the Antek's will work just fine. Cap, resistor and rectifier (standard vs. soft-recovery) selections will probably have a greater impact, IMHO. (BTW, Papa is not overly enamored with soft recovery rectifiers, even though they have become pretty cheap to use.....)
samoloko said:
Salamoko,
Please notice that the setup of a pi filter (Cpar-L-Cpar) not only depends on the inductor (L). I build my F5 with the amplimo 2x18V (650VA), Cpar1=30.000uf and Cpar2=0,1F per channel!!
Using these high capacities made it able to use an R of 0,9 Ohm instead of an L, with the benefit of coupling the very low output impedance of the transformer to the Fet's. My mains voltage is 230V, rail voltage=24.5 V, voltagedrop over R=120mV dc. As you can imagine I reduced the current limitation and the value of R11 and R12 to 0.39 Ohms.
If you have a oscilloscope and a tone generator with a nice square wave output you can clearly see the influence of the design of the pi filter especially with a low impedance load.
Have fun testing!