Hi,
I have a question about calculating the power dissipation of an amplifier for heatsink selection. I have an amplifier (Say it is a power opamp or an audio amplifier), is driving a fully (assumed) inductive load. It is a current feedback circuit (see the figure) because of driving the inductor. The Input and output of the amplifier is a sine wave at single frequency (In KHz) without any offset.
L1 is the inductive load
R3 is current feedback resistor (The loading effect of R3 is neglected)
R1,R2 is voltage feedback divider
Let;
Vs is supply voltage (not shown in the figure, it is symmetrical as +Vs/-Vs)
Im Output current (amplitude) delivered from amplifier, i.e. (I(t)=Im.Sin(wt))
Vm Output voltage (amplitude) at the output of amplifier, i.e. (V(t)=Vm.Sin(wt+Phi)), here Phi is about 90 degree because of the inductive load.
What I want to calculate is; the power dissipated by the U1 amplifier. Please note that the amplifier output is in quadrature phase with the output current and the amplifier output is a typical A/B class push-pull transistors.
What is the simplest way to calculate the dissipation without the time-domain complexity, including rail voltage offsets of sine over the push-pull output transistors etc.
I have a question about calculating the power dissipation of an amplifier for heatsink selection. I have an amplifier (Say it is a power opamp or an audio amplifier), is driving a fully (assumed) inductive load. It is a current feedback circuit (see the figure) because of driving the inductor. The Input and output of the amplifier is a sine wave at single frequency (In KHz) without any offset.
L1 is the inductive load
R3 is current feedback resistor (The loading effect of R3 is neglected)
R1,R2 is voltage feedback divider
Let;
Vs is supply voltage (not shown in the figure, it is symmetrical as +Vs/-Vs)
Im Output current (amplitude) delivered from amplifier, i.e. (I(t)=Im.Sin(wt))
Vm Output voltage (amplitude) at the output of amplifier, i.e. (V(t)=Vm.Sin(wt+Phi)), here Phi is about 90 degree because of the inductive load.
What I want to calculate is; the power dissipated by the U1 amplifier. Please note that the amplifier output is in quadrature phase with the output current and the amplifier output is a typical A/B class push-pull transistors.
What is the simplest way to calculate the dissipation without the time-domain complexity, including rail voltage offsets of sine over the push-pull output transistors etc.