Designing of a PWM based variable voltage regulator(input 220VAC output 3-5VDC) for medical light source.

[Er.Sarbottam Sapkota]

Hello friends,I am planning to design a PWM based variable regulated voltage power supply for medical light source.The input for the light sourvce will be 220VAC and the output will be 3-5 VDC.Also i am planning to embed the microcontroller to display the brightness level of the light thus producedin LCD Display of & segment Display.
Hope you will help me in designing this.

 

[Pommie]

Most countries have very strict rules on any medical device that's connected to the mains. For this reason, medical grade supplies are available and should be used.

Mike.

 

[Arch angel]

will be 220VAC and the output will be 3-5 VDC.Also i am planning to embed the microcontroller to display the brightness level of the light thus producedin LCD Display of & segment Display

That is confusing please clarify

 

[Diver300]

There are lots of designs of 5 V power supplies that have 220 V ac input. I suggest that you use one of those, and put a PWM control between the 5V output of the power supply and the light source.

What is the maximum current that the light source takes?

 

[Er.Sarbottam Sapkota]

the total current will be 10 A(Max)

 

[ronsimpson]

That is confusing please clarify

When building a power supply there must be insulation from power line to person. For medical use the isolation is larger.
This is for the power supply and the plastic case.

 

[Diver300]

the total current will be 10 A(Max)

The design of a 10 A, 5 V power supply isn't easy. It would be far easier and far cheaper to buy something like this:-
https://uk.farnell.com/xp-power/ecm60us05/power-supply-ac-dc-medical-5v/dp/1176962 and then have a device on the output to produce the PWM

Are you sure about the 10 A? Most lights are LEDs, and 50 W of LEDs is a lot.

 

[Pommie]

To do a 50W isolated power supply for medical purposes requires a good level of expertise and various levels of certification. I doubt you have that level of experience, just buy an adequately specified supply and be safe.

Mike.