Dear All,

Hope everyone is fine. Here, I am interested to discuss one query that i have designed power supply for RF transmitter's PCB, Voltage range (5Vdc , 48Vdc). I have designed in Altium designer but unable to simulate (because Spice model of ICs are not available) this supply (220Vac to 5Vdc & 48Vdc), to verify weather it works well or not ? Kindly someone review this circuit and obliged me, and suggest me with their comments if there is any problem in circuit.

Anxiously waiting for prompt reply.

Regards

 

There are plenty of things that need attention.

1) All input components Ri1-Ri4 serve no purpose but to generate heat and waste power. Ri3 and Ri4 are too high. There will be little power input.

2) Dz1 will blow.

3) Why cascaded switching supplies? Why not just use one?

 

I would add Ci1 would also inhibit the output (though that might be included in 'All input components...').

 

View attachment 204681

There are plenty of things that need attention.

1) All input components Ri1-Ri4 serve no purpose but to generate heat and waste power. Ri3 and Ri4 are too high. There will be little power input.

2) Dz1 will blow.

3) Why cascaded switching supplies? Why not just use one?

Thanks for your kind attention and reply ... please suggest me better design , if you can .. I shall be highly grateful to you for this act of kindness.. Dz1 is zener diode for 12 V regulation..

 

I would add Ci1 would also inhibit the output (though that might be included in 'All input components...').

Thanks for your kind concern.. please suggest me the better design .. and recommends me better ideas please ..

 

3) Why cascaded switching supplies? Why not just use one?
[/QUOTE]

Actually the first one is used for 12 V to 24 V and tye second one is used for 24V to 48V .. I didn’t found any specification directly 12V to 48V ...

 

(220Vac to 5Vdc & 48Vdc)

How much current at 5V and how much at 48V?
What transformer? T1 What is its output voltage.
------------------
The voltage from the transformer needs to be in the 7-40V range to make the LM2596 output 5V at under 3A.
One single LM2586 can work with input voltages of 4 to 40V.
A 24V transformer will give you 30V (about).

 

but unable to simulate (because Spice model of ICs are not available) this supply (220Vac to 5Vdc & 48Vdc), to verify weather it works well or not ?

LM2596 model - member ericgibbs posted it here

LM2586, most probably in Webench.

 

How much current at 5V and how much at 48V?
What transformer? T1 What is its output voltage.
------------------
The voltage from the transformer needs to be in the 7-40V range to make the LM2596 output 5V at under 3A.
One single LM2586 can work with input voltages of 4 to 40V.
A 24V transformer will give you 30V (about).
View attachment 204696

Dear respected ronsimpson,
Thanks for your kind cooperation, here i wanna inform you that current should be less than 3A is fine ... and i am bit confused that 220 V to 24 V transformer is available, if is it then it wil be good and suggested diagram is very good.. the last point the values used for capacitors and resistors are fine or needs to change ?? Please suggest me !!

Regards

 

LM2596 model - member ericgibbs posted it here

LM2586, most probably in Webench.

Thanks

 

UR1 Output 5V 3A input 30V 0.5A (If no loss)
UR3 output 48V 1A input 30V 1.6A
From transformer 30V 2.1A. 63 watts
We need a 220v to 24V 3 to 4A transformer.
100V 5A diodes.

 

UR1 Output 5V 3A input 30V 0.5A (If no loss)
UR3 output 48V 1A input 30V 1.6A
From transformer 30V 2.1A. 63 watts
We need a 220v to 24V 3 to 4A transformer.
100V 5A diodes.
View attachment 204751
View attachment 204753

Thanks dear respected ronsimpson for your kind help and cooperation, i will try to implement, if I found any problem I will contact you again..

Regards

 

Dear respected ronsimpson,

As per your recommendations i have designed the Power supply ckt for 5Vdc and 48Vdc. Here, i wanna ask one question, if i am interested to add one more point for 6.5Vdc. so how can i obtain the 6.5Vdc aslo form the under mentioned ckt as third output point. I found MP8606 IC can provide 6.5Vdc but current is too high i.e 6A. any other way ??

Thanks

 

What do you mean by "current is too high"?

 

What do you mean by "current is too high"?

Dear MrChips,

I mean to say any other IC or any other way tp get 6.5 V dc ??