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Sweet dreams Audio!A little 9V alkaline battery can supply almost 80W for a few milli-seconds.
That's nonsense, use the 9V battery to charge a capacitor and it will provide 80W for a short period of time.http://www-images.panasonic.com/industrial/battery/oem/images/pdf/9V_Ind_Alka_Bat_Data_Sheet.pdf gives the battery impeadence as 2.76Ω.
Maximum power theorem - Wikipedia, the free encyclopedia hmmm... well I goofed my math. it is really only 7W max.
Dan
Possibly, but not a 9VA woman gave a speech using a wireless microphone. She began to dance and cry. The spare 9V alkaline battery in her pocket was shorted by a coin and was burning her.
I read somewhere (Energizer?) that a little battery can supply 10A. Maybe an AA Ni-MH cell.
I posted the link to an actual 9V data sheet. 9V/2.76Ω=3.2A into a short circuit from a fresh 9V. P=I²R, R=0, P=0That's nonsense, use the 9V battery to charge a capacitor and it will provide 80W for a short period of time.
A woman gave a speech using a wireless microphone. She began to dance and cry. The spare 9V alkaline battery in her pocket was shorted by a coin and was burning her.
I read somewhere (Energizer?) that a little battery can supply 10A. Maybe an AA Ni-MH cell.
No, the capacitor will increase the peak instantanious power the battery can supply.I posted the link to an actual 9V data sheet. 9V/2.76Ω=3.2A into a short circuit from a fresh 9V. P=I²R, R=0, P=0
The most power that you can get is when the load resistance equals the source resistance. The maximum power available is P=V²/R, 4.5²/2.76=7.3W. Now if you are talking energy, that is a different story. You can charge a capacitor to what ever voltage, but that is energy and not power.
Dan
Can I generate 80Watts of power with a portable battery?
Not possible on a bog standard 9V since the internal resistance is almost three ohms limiting the short circuit current to 3A.No, the capacitor will increase the peak instantanious power the battery can supply.
Connect a 47,000µF capacitor with a negligible ESR capacitor in parallel the battery, it will charge to nearly 9V in 0.7s. Connect a 1R resistor in parallel and the power dissipation will be 81W at the instant you connect it.
No, the capacitor will increase the peak instantanious power the battery can supply.
Connect a 47,000µF capacitor with a negligible ESR capacitor in parallel the battery, it will charge to nearly 9V in 0.7s. Connect a 1R resistor in parallel and the power dissipation will be 81W at the instant you connect it.
I see now...I had missed that point. But then the 9V battery is not supplying the 80W, the capacitor is.I think this is the principle used for flash lights in camera. Am I right? But here he has not mentioned how long he wants 80W power.