I hv 12V 1A DC adapter but i want to convert the 12V 1A output to 9V .85A using L7809 Voltage Regulator
Can Any one suggest me how to do this and what should be the connection diagram or schematic to achieve this result

 

Just follow the information on the LM7809 data sheet regarding input and output decoupling capacitors. You will need a small heat sink on the LM7809 as it will be dissipating 2.55 watts.

Les.

 

hi,
The 7809 drop out voltage, ref this clip from the d/s, shows a 12V input to the 7809 will be OK.

 

WHAT SHOULD I DO TO GET THE DESIRED RESULT

 

Just follow the information on the LM7809 data sheet regarding input and output decoupling capacitors. You will need a small heat sink on the LM7809 as it will be dissipating 2.55 watts.

Les.

I HAVE HEATSINK ON IT BUT STILL HEATING
I HV A TPLINK ROUTER THAT REQUIRES A INPUT OF 9V .85A BUT DUE TO IMPROPER CURRENT MY ROUTER IS GETTING SWITCHED OFF AFTER RUNNING A WHILE

 

hi,
The 7809 drop out voltage, ref this clip from the d/s, shows a 12V input to the 7809 will be OK.
View attachment 181999

ACTUAL PROBLEM IS I DONT UNDERSTAND DATASHEET I DONT KNOW HOW TO READ IT SO IT WOULD HV BEEN VERY HELPFUL FOR ME IF YOU COULD GIVE ME THE SCHEMATIC TO ACHIEVE THIS RESULT

 

hi,
What size/type of heatsink and what is the sink and ambient temperature.?
E

 

SIMILAR TO SIZE OF REGULATOR AND ITS A TYPE OF ALUMINIUM AND sORRY SIR I HV NO GADGET TO MEASURE THE TEMPERATURE BUT IT WHEN I TOUCH IT IT CAN BURN MY FINGERTP 10-15 SECOND

 

This is the schematic for connecting the LM7809 (Or any of the LM78 series of regulators.)


The regulator is probably shutting down to protect itself due to too small a heatsink. When you buy a heatsink it will have a rating of Deg. C/W. This means it's temperature will rise by that number of Degrees C for every watt dissipated. I would aim for it not to get above 40 Deg, C

Les.

 

Hello,

@Vipul Kumar 1 , Again, Please do not use ALL capital characters. It is like shouting.

Bertus

 

Hello,

@Vipul Kumar 1 , Again, Please do not use ALL capital characters. It is like shouting.

Bertus

ok thank you sir i will tk cr of that