| ??? 04/01/08 15:52 Read: times |
#152841 - Speakers are what they are ... Responding to: ???'s previous message |
Winston Hoon said:
how high impedance should the speaker be?
yes, it is my homework,I just need some help that all. You won't be able to change speaker impedance. Some speakers are 16-ohm types, but 8 is the most common. You won't be able to change that. The microcontroller can't do much to an 8-ohm load. A resistor won't help, though it may protect the microcontroller from damage which may result from attaching an output to such a low impedance. I would suggest you obtain and carefully read the specifications of the microcontroller. If you use an LM386 or equivalent operational amplifier you can then drive the speaker from the very high impedance of the microcontroller. The LM386 is intended for that purpose. Of course, you will have to obtain and read its datasheet. The point of this assignment probably is to point out to you that not every problem can be solved by connecting something directly to the microcontroller. RE |
| Topic | Author | Date |
| driving a speaker | 01/01/70 00:00 | |
| Amplifier needed | 01/01/70 00:00 | |
| 8051 Output port drive current | 01/01/70 00:00 | |
| current | 01/01/70 00:00 | |
| Links | 01/01/70 00:00 | |
| links | 01/01/70 00:00 | |
| Think about it! | 01/01/70 00:00 | |
| speaker | 01/01/70 00:00 | |
| ... or higher-impedance speaker | 01/01/70 00:00 | |
| impedance | 01/01/70 00:00 | |
| Speakers are what they are ... | 01/01/70 00:00 | |
| impedance answer | 01/01/70 00:00 | |
| piezo | 01/01/70 00:00 | |
| The reason you're in school is to learn | 01/01/70 00:00 | |
| Library? | 01/01/70 00:00 | |
| research | 01/01/70 00:00 | |
You can use a transistor, but if you read ... | 01/01/70 00:00 |