dc-filtering-ac-power-station

Status
Not open for further replies.
Jump to Latest
jh6you

jh6you

Disabled Account
Joined 2002
#1
Hi

Days ago, I fixed dc-blockers for my BOSOZ and F1 and found that they were working well (reference thread: Forte Audio 1a). And, I got real effect much better than other tweaks with quality of wires or components.

Therefore, I am going to make, say, a dc-filtering-ac-supply-station as shown below. The chassis will be of aluminum and will be directly connected to the earth. This station will cover Pass F1, BOSOZ, CD player and DVD projector.

Do you have any opinion or advice?
Particularly, regarding !!! SAFETY !!! of life. . .

Regards
jH
 

Attachments

  • dc-filtering-ac supply station.jpg
    dc-filtering-ac supply station.jpg
    50 KB · Views: 2,562
#5
Hi Lumanauw

I'm fine thanks 😀

The bigger, the berrerrrrrrrr . . . . . . maybe.
The polarized electrolytic capacitor doesn't like to see overvoltage or reversevoltage. If capacitor sees the overvoltage or the reversevoltage, it becomes hot temper, and boils the yellow blood inside, and gets high blood pressure, and BAM !!!!!!! Meanwhile, the barrier potential of the bridge diode is about 0.7V. Luckily, the capacitor hardly see voltages higher than +/- 0.7V in this case. -- my hope[i/]

Question: how much reversevoltage we could safely ignore?
Lumanauw, this is your homework. Solve it and tell me 😀

Regards
jH


Thanks, Diar and steenoe.
 
#13
Hi,
I do not like your lack of mains isolation inside that metal box!!!.

Are you using mains rated input and output connectors? They look like screw locked DIN plugs,

You have a lot of exposed and/or uninsulated connections inside the box. It looks unsafe to my eye.

Have you connected the DC blocking capacitors in the neutral line or the live line? One is at 220Vac and the other is nearly zero Vac.
I would prefer that all the blocking was done on the neutral line.

What capacitor values did you finally choose?

Can you post a final schematic?
 
#14
AndrewT said:
Hi,
I do not like your lack of mains isolation inside that metal box!!!.

Are you using mains rated input and output connectors? They look like screw locked DIN plugs,

You have a lot of exposed and/or uninsulated connections inside the box. It looks unsafe to my eye.

Have you connected the DC blocking capacitors in the neutral line or the live line? One is at 220Vac and the other is nearly zero Vac.
I would prefer that all the blocking was done on the neutral line.

What capacitor values did you finally choose?

Can you post a final schematic?
Click to expand...
yes, it looks scary. Lots of uninsulated wires soldered p2p inside metal box. Goes tough along the lines what i have seen in S-E Asia, household installations look sometimes !#"%¤& scary. 😀

------
Does it matter if caps are L or N connected? L and N can be swapped any moment by installing wall pluq reverse so it has to be built accordingly.
------

Why four bridges? One would do as well if it has enough high ratings.
 
#15
:att'n: Risk of electric shock :att'n:
:att'n: For safety reason, never make this! :att'n:

Hi

Pls remember that behind the picture, I have a MCB (miniature circuit breaker). I have a life insurance and a lovely wife. And, she has a life insurance and a husband.

The metal box and all metal surfaces are earthed. The inside wires are naked. But, I could have no chance for me to enter inside the box.

Each cap has 10,000uF/50V. Each bridge rectifier has 1,000V/35A rating. I assume that, when the bridge rectifier has forward bias, the forward bias resistance would be ignorable above about 0.6V. Therefore, this dc-blocker could block dc of about max 1.2V. And, the current flow in caps would be low in both forward and reverse bias. Probably, the size of caps might be bigger than necessary.

:att'n: Risk of electric shock :att'n:
:att'n: For safety reason, never make this! :att'n:

Never make this. Try to find a professional manufacture and, only if they prove safety, buy it.

Regards
jH
 
#16
Hi Mzzj,
I had not taken account of plug reversal.
In the UK this cannot happen unless some idiot wires up the plug top with the colour coded wires reversed.

Jh6,
the lid is not earthed. If you dropped this into the box. Life insurance activated.
In UK, best practice is all removable metal panels have an earth connection.
 
#19
I am not writing to defend unsafe layout.
:att'n: :att'n: Risk of electric shock :att'n: :att'n:
I am just describing what I have done.
Of course, all should stay away from the box when its inlet plug is connected to the wall outlet.

Regards
jH
 
#20
:att'n: This kind of project should only be attempted by those fully experienced in high voltage safety practices.:att'n:
Constuction is best done in a plastic box, with no metal screws showing outside. Non-reversible mains grade connectors are essential too.

Remember also that other people or pets may touch the equipment who do not know the dangers. It must be made safe for all.
 
Status
Not open for further replies.
Top Bottom