Hi to everybody!

I think to have a problem with switching power supply.

When I use this kind of power supply my circuit begins very sensitive to the electro-static discarge.

I use 2 Voltage regulator to lower the Voltage of power supply from 24V to 5 V.
The first one lowers the voltage from 24 V to 12 V.
The second one lowers the voltage from 12V to 5 V.

When a ESD happens, the tension on the output of second voltage regulator is lowered and its temperature begins to increase.



You have some council in order to resolve my problem ?

Thx

 

hi,

is this the kind of circuit that you have?

a lot of heat will be dissipated by your 12 and 5 regulators considering that your 12 has to drop 12v and your 5 has to drop 7. ideally voltage drop should only in the range of 3v to 5v at most in order that regulation would be reliable and likewise the chip operates at a lower temperature.

the regulators should be installed with adequate heatsink size like a 1.5" (H) by 3" (W) by 1.5mm to 2mm (T)

 

Originally posted by mozikluv@Nov 3 2004, 03:29 AM
hi,

is this the kind of circuit that you have?

a lot of heat will be dissipated by your 12 and 5 regulators considering that your 12 has to drop 12v and your 5 has to drop 7. ideally voltage drop should only in the range of 3v to 5v at most in order that regulation would be reliable and likewise the chip operates at a lower temperature.

the regulators should be installed with adequate heatsink size like a 1.5" (H) by 3" (W) by 1.5mm to 2mm (T)

[post=3296]Quoted post[/post]​

Hi!

My circuit is similar to your the only diffent is that I use a switching power supply instead of a diode bridge.