Schematic diagram of power supply

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Bearbear40

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Required help in a schematic diagram of a power supply.
Conditions as per below:

input: 230V ac
output1: 24V dc unregulated
output2:9V dc regulated

Any expert is able to help in this?

Thanks
 

Hi,
What about Ampers and possible humms pls?

Otherwise I would say; you need a trafo with two secondaries (or even two separated transformer), so ca. 24VAC and 3V ac, then both bridges & some puffer capacitancies, values are depending of your load and possible humms... Maybe these transformer is self to make or will be a custom product.
But remember pls; these voltages wil be not exactly 24 & 2.9 V DC; if you must have exact voltages_ is better to use regulators, I would take i.e. for 2.9V in all cases a regulator!
K.
 

well buddy i suggest to visit the site
electronics-diy.com
hope it solves ur problem

Added after 5 minutes:

hey check the link hope it works for u

**broken link removed**
 

Use a 0-24 volts transformor, rectify and filter to get 24 volts unregulated, and then use a 3 terminal regulator such as LM7809 to get 9 volts regulated thereon. But you didnt mention what is your "current" requirement.
Cheers
 

Bearbear40 said:
Required help in a schematic diagram of a power supply.
Conditions as per below:

input: 230V ac
output1: 24V dc unregulated
output2:9V dc regulated

Any expert is able to help in this?

Thanks
Click to expand...
:idea:

Hi
You need to find out your need of currunt fist.
There is two ways to do it.
1 If you buy ready made 24v smps power supply and then use fixed voltage regulator whitch is 7809 takes upto 1amp output and 78M09 is 500MILI AMP this are 3 pin regulator you can use fuse inline with the input of regulater upto 1AMP for 7809 and 500MILI AMP for 78M09.

2 Buy a trnsformer as your need of currunt center tap (22-0-22) or (0-22) for center tap use 2 rectifier diode according to your currunt need and filter cap 2200MFD 35V with this you got 24V unregulated and then use this output with the regulator above but dont forget to use a fuse upto 1AMP for 7809 and 500MILI AMP for 78M09.
 

    B

    Bearbear40

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Sorry... But I am unsure of the current required and I am also a newbie in this topic...
Hope that an expert is able to help me learn more by attaching a diagram for better understanding...

Thanks
 

Hi Bearbear,
Nothing is problem_nobody is with some electronic knowlidge bornd...
You can assume (hopfely), that your circuit needs i.e. 10/20W or not more as 1A from 24V & eventually not more as 2A from 9V?
Sorry I did a mistake, than a roed first your script as you will need 2.9V...
In that case is a standard regulator, as Pranam proposed too, usable for 9V and maybe you dont need regulated voltage for the 24V.
For more exact or seriose answer we need power/current data pls!
K.
 

Bearbear40 said:
Required help in a schematic diagram of a power supply.
Conditions as per below:

input: 230V ac
output1: 24V dc unregulated
output2:9V dc regulated

Any expert is able to help in this?

Thanks
Click to expand...
 

    B

    Bearbear40

    Points: 2
    Helpful Answer Positive Rating
Hi,
dont forget pls. the high need for cooling of ca. 15-18W (if you will consume 1A) wast heat !
For the 9V regulator you need a ca. 14-15VDC at the input, but from the transformer of 20-22V secondary; you will become ca. 28-30V DC!!.
These pwr supply is better to realize (as I did write it earlyer) with trafo of 18V (if you dont need regulated 24 DC) and a second trafo or secondary winding of ca. 12V ac...
So will you need relative minimal wast heat to dissipat, but a sure working, even with lower mains voltage as nominal...
Good realisation!
K.
 

In the circuit diagram posted if a 100n (0.1uF) capacitor is added in parallel to the two electrolytic capacitors it will improve the performance. For negative supply regulators lik 7909 etc this is a must else it starts oscillating and heats abnormally.
Also it is a good practice not to use higher value capacitor at the ouput of three terminal regulators as it draws heavy surge currents (100uF is high).
 


Hi

You can have 100nf cap to be fitted accros filter caps if you going to use this psu for digital or rf use. To avoid any noise you bettere of having this 100n caps accros the deivce supply and ground pin for repal rejection.

If regulator is for output currunt of 1amp there is no chance it will draw more then 1amp and that is why i ask you to have 1amp fuse inline.

For LM7809 is negative voltage regulator you need to use 2 more diode and filter cap and for that you have to use center tap transformer and same as positive supply use fuse inline.

At the output of regulator you dont have to use larg caps bucause its a regulator and you are not droping voltage to 9volt by droping resistor.

Try having only 47mfd at the output of regulator and check with the meter in load cundition is there any repal or noise. This regulator needs heatsink if you going to draw 1amp all the time.

Rajguru
 

Hi friend,
the OP didnt speak over 7809 & did especially never speak over hes need of negative voltage!

BTW;
of course, you can use 7809 for negative regulating, but its not very good idea_over long years you will find dedicated component_7909_ for these goal...
7809 is (only)usually an 1 A regulator, with VERSIONS_depending of vendor & package_between 0.5...1.5A!
K.
 

Thank you people... Help me a lot...
Btw, I got into a website and they happen to also have to design the power circuit, I don't really quite understand:

Input: 12V Lead Acid Battery
Output: 5Vdc

Does it mean that transformer is replace by the 12V lead acid battery? And also to get the output, I need the LM7805? If so, how does the diagram looks like???

Thank you very much
 

Hali,
link these website pls...
K.
 

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