Laptop switched power to run a 12v heated car seat for office chair

[maxcap]

Please Can anyone tell me why a 90w switched laptop supply wont heat the car seat but just causes the led on the cigar lighter plug to blink?

I tried a 12v 6a led supply and that didnt work.

Car seat 12v 35w on Low 50w on high setting.

Cheers!

[stj]

Re: Laptop switched power to run a 12v heated car seat for office chair

first the 90w is probably a lie covering 75w
second, a heating element has a cold resistance much lower than running, so startup current is probably atleast 3x what you expect.

[eccerr0r]

Re: Laptop switched power to run a 12v heated car seat for office chair

What car seat warmer? What power supply?
A typical 90W laptop PSU is 19V 4.5A and if the seat warmer is 12V nominal it will draw almost 60% more power possibly overloading circuitry...

Or there could be electronics in the plug that disables when out of spec (in either direction) voltage is detected?

35W =~ 3A, 50W =~ 4.5A...

[kaboom]

Re: Laptop switched power to run a 12v heated car seat for office chair

first the 90w is probably a lie covering 75w
second, a [bheating element has a cold resistance much lower than running,[/b] so startup current is probably atleast 3x what you expect.

For hi-watt-density, like toasters, dryers, lightbulbs, etc.

If these are aything like the elements in heating pads, they'll be something like a power resistor, but "flatwound" on a Steatie or mica former.

Also, seat heaters are inside fabric after all, hopefully with some insulation- hardly a high-watter...

maxcap, what's the rated wattage of the heater? If it draws 75W at 12V (1.92ohms), it will overload a common 19V laptop supply- it'll attempt to draw nearly 10A/~190W!

[CapLeaker]

Re: Laptop switched power to run a 12v heated car seat for office chair

Does that heated seat actually work on a regular battery or on a big PSU? Not that there is something wrong with whatever is inside that cigarette lighter plug circuitry?