13-07-2017, 02:23 PM
(13-07-2017, 01:54 PM)unrealdave Wrote: OK
so are you saying if the impedance is not matched it wastes power?
If you have two resistors in series the same current will flow through them. The power is I^2 * R so you have the most power when I and R peak. Leave one resistor value fixed and adjust the other. Raising total resistance lowers I . Reducing total resistance allows the current to increase but the higher current drops more power across the fixed resistor. The fixed resistance is you circuit and the variable is the phones so you get maximum power across the phones when the match the circuit impedance.
Hope this makes since. You could use a simple circuit use a 10k fixed then vary the load 5k, 10k, and 15k using a 10 volt supply.
Also in a radio circuit you are power limited. In the example above the battery will supply power as need. I a radio as you load the circuit you kill the circuit Q and lose power.
73
