[library]

Hello, all

I am going to built the cornet phono soon. Presoldering research is about to finish. I have several questions regarding the power supply part of the cornet phono. Basically, I am going to enhance the power supply part including the transformer. I must be careful about it, so pose several questions.

1. Can I use a Bridge diodes instead of bridge structured 4 single diodes?

I cannot get 4 single diodes in such a spec here. Instead, I am going to use this bridge diode : KBPC101  KBPC101  10A,100V, Bridge Diodes
I think it is ok to replace four diodes with this one. But I need a guarantee from anybody experienced.

2. Where is the best place to put a choke for the power supply?
I guess choke will remove any ripple from the source current, so will put a choke there. I think the best place to put a choke is just next to R2 (6K8). But I don't know what will be the value of the choke. 3H, 20Ohm will be OK? Please make any corrections and suggestions.

3. How can I calcurate the value of resistors for voltage calibration?
I read several suggestions from Jim to cope with various voltages. He suggested to change the value of resistors to compensate low or high voltages for correct voltage supply. Maybe it is a simple V-I-R theory but I have no clue. What is the theory behind it? For example, the standard elec here is 220V 60Hz but it is only 210V at my home. I need to make the voltages precise.

Thanks in advance.

Regards,

[hagtech]

Yes, you can probably wire in a bridge diode - just make sure it is schottky type!

If you are going to make a choke-input style power supply, you'll need a very different power transformer.  Use the design calculator at:

http://www.hagtech.com/theory.html#choke

This type of supply must be tuned carefully for stability.  As always, I recommend building the stock version first, then modify.  Nice to have a known reference starting point that works.

jh

[library]

Mr. Hagerman

Thanks for you reply. Your web support and the design programs are fantastic!
I am going to study more about the choked power supply. Meanwhile, I will be with your standard circuit just with bridge diode. Then I can apply the choked power to the new cornet2.

Thanks again!