Overdriving voltage regulator input?

[[email protected]]

So if I have a DC-DC voltage regulator that expects 7 to 13.8V on the
input, will I fry anything by feeding it 17 volts?

Not sure what the voltage regulator output is (this is a consumer
electronics device that uses about 500mW). The 17V input is coming from
an unregulated wall wart rated for 12V @ 1000mA, so I imagine the
voltage drops a little bit when the device is turned on.

Thanks!

 

[martin griffith]

On 25 Mar 2005 08:43:46 -0800, in sci.electronics.design

So if I have a DC-DC voltage regulator that expects 7 to 13.8V on the
input, will I fry anything by feeding it 17 volts?

Not sure what the voltage regulator output is (this is a consumer
electronics device that uses about 500mW). The 17V input is coming from
an unregulated wall wart rated for 12V @ 1000mA, so I imagine the
voltage drops a little bit when the device is turned on.

Thanks!

Put a dummy load on the walwart, to simulate your regulator, measure
the V and take it from there.

Without knowing more about the design of your reg............



martin


Opinions are like assholes -- everyone has one

 

[[email protected]]

So if I have a DC-DC voltage regulator that expects 7 to 13.8V on the
input, will I fry anything by feeding it 17 volts?

Not sure what the voltage regulator output is (this is a consumer
electronics device that uses about 500mW). The 17V input is coming from
an unregulated wall wart rated for 12V @ 1000mA, so I imagine the
voltage drops a little bit when the device is turned on.

Thanks!

if 13.8v is the upper limit of its acceptabel input, quite likely. Use
one suitably rated.

NT

 

[Rich Grise]

if 13.8v is the upper limit of its acceptabel input, quite likely. Use
one suitably rated.

It looks like the wall wart is unregulated, and droops to 12V at
rated current - a shunt regulator at 13.75 or so volts would make
the wall wart usable, although it might be more hassle than it's
worth.

Cheers!
Rich