SMPS Open Project

[cristi]

This SMPS is intended to be used for Audio Power Amplifiers, Class AB or Class D. The schematic, PCB Layout and BOM version 1.0 are attached in the following PDF file. The Output voltage is +-50V at 5A continuous, the SMPS is able to deliver 7A peak for 5 minutes or 10A peak for 1 minute. The maximum output power is thermally limited, by the heatsink and components maximum temperature. The output ripple is about 10mV with no-load and below 200mV at 5A. The step load response is very good, for a step load of 1 to 5A the output voltage variation is less than 2V. Since this SMPS is without PFC, the input current will be non-sinusoidal, the current drawn from the mains will an average of 5A for 220V AC at maximum output powe and 10A for 110V. The average efficiency is 87% and the efficiency at maximum output power is 90.7%
This is the first version and there is room for improovements, on the next versions.
Take a look at the attached schematic, gerbers and BOM.

[cristi]

PCB's came few days ago, i assembled few boards already and i made some tests.

[cristi]

PCB's available for sale. price 6.99 Euro or 10.49USD including shipping worldwide. all the parts including transformers, inductors, capacitors, transistors, diodes, IC's, etc. available as well.
you may check the price list here: http://connexelectronic.com/index.php/c ... f4t811knj6
i will post a detailed price list with price for each component as well, for those who want to purchase only some components.

[cristi]

more photos, measurements and tests results will be posted tomorow.

[moro]

That's a nice one. By the way, where did you get the pcb done?

[cristi]

some test results. photos can speak for themself. on top of the instuments stack, is the Power Analyzer. this measure the input current, voltage, power factor and power. next, the upper scope, the digital one monitor the output vawe, directly on the transformer pins. the lower one, has one channel DC coupled on the bridge, probes set to x10 and scope at 5V/div, 5uS and another channel AC coupled, probes x10, 5V/div, 5us and is connected to vbus. what can see there is the AC ripple. the two multimeters from below the analog scope measures the output voltages, one for positive, one for negative. at the bottom, with the audio analyzer i measure the output voltage ripple at 3, 5 and 6A. the probe is x10, so multiply with 10.
on the other side lays the DC electronic load. because is rated at just 300W, i connected in series 2 power resistors to limit the maximum power, otherwise i cannot load the smps with more than 300W. the current reading is accurate, but the voltage reading should be added to the voltage drop on the resistors, wich is proportional with the current. anyway for accurate voltage reading, i use those 2 lab. multimeters below the scope.

Enjoy.

[moro]

here is my yahoo id: moro2yeah let`s talk a bit

[dudaindc]

I have to try this board...

[djdoru]

SNC00135.jpg

50 PCB's arrived in Romania yesterday.
those which will follow this conditions viewtopic.php?f=11&t=5 will get the PCB for FREE

50 de PCB-uri au ajuns deja in Romania.
Cei care se incadreaza conditiilor expuse aici vor primi PCB-ul GRATIS.
Demonstrati ca sunteti oameni si veti fi rasplatiti.

[andrei_gradu]

Nice project
I have made one like this for my university final project, and worked fine.

How it`s made the transformer, E and ETD, it shows like made in factory.
And another question, Why is complicate the voltage reaction? Why not use only 2-3 zener diode and one rezistor?

I do not like the current protection because stops completly the power amp and you remain without muzic in the midle of the party, curent protection may be implemented like in welding inverters.