Hello,

The diodes are present to protect the stabelizer chips from backflowing currents.

Greetings,
Bertus

 

Hello,

The diodes are present to protect the stabelizer chips from backflowing currents.

Greetings,
Bertus

Hello,

Is it ok to use RS207 Rectifier for the PSU ?

 

Hello,

That will do fine.
If you are going to use the powersupply for both boards, increase the buffer capacitors to 2200uF.

Greetings,
Bertus

 

Hello,

That will do fine.
If you are going to use the powersupply for both boards, increase the buffer capacitors to 2200uF.

Greetings,
Bertus

Thank you ,
Yes ! as per your advise , i am definitely going to use the Transformer for powering both the boards, as it is powerful enough .
Noted about using 2200uf Capacitor .

 

Hello,

You could try something like this using transformer 6:

Greetings,
Bertus

Hello.

I can't figure out , what is the Value of Capacitors that are grounding the outputs , is it 1 microfarad & 2.2 microfarad ?

 

Hello,

When you look in the datasheets of the LM78XX and 79XX you will see there are always two small capacitors around the stabelizer.
One at the input and one at the output.

The capacitors are there to prevent the stabelizer from oscillating.

In the schematic I gave you (from a dutch site) there are only the capacitors at the output (1 uF at the 78XX and 2.2 uf at the 79XX).

Greetings,
Bertus

 

Hello,

When you look in the datasheets of the LM78XX and 79XX you will see there are always two small capacitors around the stabelizer.
One at the input and one at the output.

The capacitors are there to prevent the stabelizer from oscillating.

In the schematic I gave you (from a dutch site) there are only the capacitors at the output (1 uF at the 78XX and 2.2 uf at the 79XX).

Greetings,
Bertus

Hello,
Understood , thank you for your reply.

 

Hello,

You could try something like this using transformer 6:

Greetings,
Bertus

Hello ,

I finished building the PSU board , i have attached the picture .
will be testing the Project today & will give updates .
Plz do let me know if you have any comments .

 

I have the writeup for the project. Its power supply voltages are not mentioned.
The linear LM3914 voltmeter IC should be a logarithmic LM3915 VU meter IC.

The LM391x has LED currents set to 12mA. If the MODE switch is set to BAR, the supply is 12V, the LEDs are 2V red ones and are all turned on then the LM391x will dissipate 1.2W and will be extremely hot.

The project has the problem that the LEDs are multiplexed so their 12mA peak current will look dim with an average current of only 1.2mA.

 

Hello,

Did you use a second bridge rectifier for the second board?
You can connect the second stabelizer direct afther the brige of the first board (on the positive capacitor).
When connecting the grounds together now there will be problems.

Greetings,
Bertus

 

Hello,

Did you use a second bridge rectifier for the second board?
You can connect the second stabelizer direct afther the brige of the first board (on the positive capacitor).
When connecting the grounds together now there will be problems.

Greetings,
Bertus

Hello ,

I have simply Connected the small PSU Board to the AC line from the transformer.
The small board is using a rectifier Chip RS 205.

 

Really Frustrated & Sad ,
for some reason , the transformer just gave up , It seems it has internally burnt , its Like a Hotrod now :-((( .
I did check the PSU boards before i connected them to the Analog & the digital boards , they were working fine , this happened only after i connected Analog & the Digital Boards to the PSU.

"Details of the Test"

Connected every thing for test run,
Seems op amp was not working ,
The digital circuit seems to be working fine , once i switched the power supply ON & connected the audio signal to the board, the lights in the matrix started Dancing . for a moment i thought the Project is a success ,not until i disconnected the audio signal , even with out the audio signal the Lights were dancing , it seems its the LM3914 IC which was doing that
. Wanted to check further whats the Problem & the Transformer Gives up .

 

Hello,

As I told you you would expect trouble the way the powersupplies where connected together.
Can you make a schematic how you actualy did connect the powersupply-boards?

Greetings,
Bertus

 

Hello,

As I told you you would expect trouble the way the powersupplies where connected together.
Can you make a schematic how you actualy did connect the powersupply-boards?

Greetings,
Bertus

Hello,

Yes i understand , it seems I committed a very small error which cost me a Very good transformer .But its ok , i guess it was an error to learn from.

I have attached the Schematic .

 

Hello,

As you can see now the second brigde rectifier did short the transformer when you connected the - to the ground.

Here is what I had in mind with the second stabelizer:

Greetings,
Bertus

 

Hello,

As you can see now the second brigde rectifier did short the transformer when you connected the - to the ground.

Here is what I had in mind with the second stabelizer:

Greetings,
Bertus

Hello,

Thank you for the Schematic ,will consider it aswell.
I'll probably buy a new transformer Tomorrow & test the Project.

 

Hello,

You could try something like this using transformer 6:

Greetings,
Bertus

Hello ,

Bought a New transformer (the one which you recommended).
I really wish to avoid blowing this one up .
I have attached a picture of the transformer, I am a little confused regarding the output of the transformer ,
Which one is Ground (common) & which ones are the positives ?
As i see here its SEC1 = pin 6&7 , SEC2= 9&10 .

 

Hello,

With the shown transformer you can make the center tap by connecting 7 and 9.
The bridge can be connected to 6 and 10.
(the dots show the same phase).

Greetings,
Bertus