Help build a powersupply

[misel019]

Hi, im newbe in the world of uc. my group leader command me to convert a power supply 48V to 12V 1A (with uc3844) by using any of microcontroller. means i cant use uc3844 i need to use any micro controller.

i usally work with uc by 5V circuit i dont know anything about SMPS.

how can i convert that circuit any suggestion..

_Misel

 

[john blue]

it is neccessary to use a uC? you can always use the SMPS available in the market

 

[misel019]

yes necessary its an assignment for me to do with uc.

 

[sreekanthr.ele]

Are you want to convert dc 48v to dc 12v and are yoy using transformer,

If you are using a transformer no need to use a micro controller, include the rt and ct circuit to give pwm by a mosfet.

otherwise you can use LM2576HVT-12 ic directly, it is very simple construction and supports upto 3A.

regards
Sreekanth

 

[john blue]

Read the datasheet of uc3844, get to know how it works, its an AC/DC and DC/DC converter. Mostlikely you just need to input PWM pulse to it

 

[boonserb]

Why you use 48V and 48V is AC or DC ? If you want smps you can used viper is step down smps of ST. www.st.com/stonline/books/pdf/docs/15232.pdf

 

[misel019]

yes 48V DC is the input side and i need to use a current transformer and IRF740 i need to give pulse on IRF and using RT/CT i nedd to perform PWM in that portion im im in big problem to set duty cycle of PWM changing

 

[boonserb]

Hmm... You can used LM2576HVT-12 ic directly follow to "sreekanthr.ele" post #4 --> www.national.com/ds/LM/LM2576.pdf

 

[misel019]

thanks for the reply trying on that