Timeline for How can we drive an 8 ohm speaker if it can only support around 1.5-2 watts for an Audio Amplifier Circuit?
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Jan 23 at 10:34 | vote | accept | jaxillrplusone | ||
| Jan 23 at 10:33 | answer | added | geekyhez | timeline score: 1 | |
| Jan 19 at 15:02 | answer | added | periblepsis | timeline score: 4 | |
| Jan 19 at 14:48 | comment | added | glen_geek | Jax, You're making your own darlington from two transistors? The first one can be a 2N3904, because it only passes fairly low current. But the second transistor must pass a great deal more current, and should be a power transistor, likely on a heat sink. It's emitter resistor should be small, below 10 ohms so that about 0.8 A flows. You should look for a transistor whose \$IC_{max}\$ is above 2A. | |
| Jan 19 at 8:52 | comment | added | Ste Kulov | Try AC coupling between stages and setting a new (and higher) DC bias point for the emitter follower (even higher for darlington). See where that takes you. Also, learn how to hold ALT while probing the transistor to see its power dissipated. LTspice won't tell you if something will burn up in real life. It's up to you to see the numbers and translate them into something catching fire or not. | |
| Jan 19 at 6:55 | comment | added | jaxillrplusone | @glen_geek I'm not that well versed with darlington pairs do you have any suggestions to replace 2N3904? | |
| Jan 18 at 20:09 | comment | added | periblepsis | Jax, I think I keep seeing you post over and over on this same topology. It's not going to work. You need to break yourself of this. So stop thinking there's a way to fix it. There isn't. It's the wrong tool for the job. Full stop. | |
| Jan 18 at 14:26 | answer | added | AnalogKid | timeline score: 1 | |
| Jan 18 at 14:24 | comment | added | glen_geek | Seems you're focus is on a Class-A design. If you proceed this way, you're move to Darlington is in the right direction. However you'll need a bigger transistor in the Darlington-pair than 2N3904, with DC bias far greater so that AC power output is larger. | |
| Jan 18 at 13:45 | comment | added | unawriter | Get an audio amp IC. If it's forbidden try a discrete push-pull.amp. If it's forbidden, too, you must improve your current attempt substantially. You very likely have seen this case electronics.stackexchange.com/questions/697554/… Maybe today is a good day to read it. A single ended linearly amplifying output stage will unavoidably dissipate at least 2W for 2W audio AC output, probably more, because you want to avoid inductive parts, I guess. | |
| Jan 18 at 13:02 | comment | added | Dave Tweed | All of these schematics and waveforms are useless unless you show us the reasoning and the equations you're using to come up with these component values. We also need to see the rest of the requirements -- specifically, what are the characteristics of the signal source? Only then can we talk about where you're going wrong. | |
| Jan 18 at 12:57 | history | edited | Dave Tweed | CC BY-SA 4.0 |
fix formatting
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| Jan 18 at 11:15 | history | edited | toolic | CC BY-SA 4.0 |
added 3 characters in body; edited tags; edited title
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| S Jan 18 at 11:13 | review | First questions | |||
| Jan 18 at 11:15 | |||||
| S Jan 18 at 11:13 | history | asked | jaxillrplusone | CC BY-SA 4.0 |