Power Amplifier and Exciter, Impedance / Power

[student_173]

Hello. I have a question regarding an power amplifier (signal generator). I have three exciters and want to connect them to the power amplifier. One exciter have a impedance of 8ohm and power of 25 watt. The ampliefier have one output with the electical data: 4 ohm : 500watt; 6ohm: 330 watt and 8ohm : 250 watt. now my question. It is possible to connect all three exciters over the one output from the apmpliefier? If yes, why?
Thanks for help!

 

[osilmag]

Those are the max or ideal ratings telling you how much power they can supply. At 8 ohms, 250 watts your amplifier should be able to put out ~5 amps. So, your three exciters at 8 ohms 25 watts would require 1.6 amps each in parallel or 1.7 amps in series. If I did the math correctly, you should be fine.

 

[hutchphd]

Can you elucidate the math here? I am lost.

 

[berkeman]

Welcome to PF.

I have three exciters and want to connect them to the power amplifier.

What's an exciter?

 

[osilmag]

Can you elucidate the math here? I am lost.

$250=I^2 * 8$
$I=5.5$
That would be the current for the amplifier.

$25=I^2 * 8$
$I=1.6$
That would be the current to each "exciter" in parallel.

 

[tech99]

There seems to be a linguistic confusion here about inputs and outputs and what is driving what. May we have a better description of the set up?

 

[DaveE]

OK, I guessing that you have an audio power amplifier and you want to connect 3 speakers to a single output. Is that correct? I'm confused about the specifications you listed. For example:

I have three exciters

One exciter have a impedance of 8ohm and power of 25 watt.

what are the others? Please try again with more clarity.

If they are all the same, then yes I think it should work with the loads in parallel. Then your equivalent load would be 2.7Ω, with 75W, 5.3A, 14V at the limit. I think series may not work because of the higher voltage required (42V max). Amplifier stability will probably be OK. The specs imply at least a 4Ω - 8Ω range, 2.7Ω isn't too far away from that. If you're an audiophile, you may want more damping, IDK.

Edit: Series should also work.

 

[willem2]

Sure the amp can handle the exciters. Can the exciters handle the amp?
It seems the amplifier can produce 125 V Rms to put 500 W into a 4 ohm speaker. you would blow up an 8 ohm 25 W exciter at more than 10% of the maximum signal. Even with 3 exicters in series you get about 28W per exciter.