| ??? 05/02/09 18:15 Modified: 05/02/09 18:25 Read: times |
#165012 - You use a Darlington, ... Responding to: ???'s previous message |
...but you don't treat it like that. The base current is much larger than needed. The 2N3906 takes also too much base current. This is a big waste of supply current! The global warming begins in your circuit...
There's no need to take smaller resistances than R1=10k, R2=10k and R3=7k5. As you mentioned, R4 can be omitted. Kai |
| Topic | Author | Date |
| Driving TIP120 from 8052 | 01/01/70 00:00 | |
| It is the Current | 01/01/70 00:00 | |
| Use this type circuit | 01/01/70 00:00 | |
| Thanks, I'll give it a try | 01/01/70 00:00 | |
| 0.1A | 01/01/70 00:00 | |
| Michael circuit is fine with some diff values. | 01/01/70 00:00 | |
| Success! | 01/01/70 00:00 | |
You use a Darlington, ... | 01/01/70 00:00 | |
| Check values | 01/01/70 00:00 | |
| is Q2 not a bit overkill? | 01/01/70 00:00 | |
| Base current and transistor beta | 01/01/70 00:00 | |
| logic level MOSFET | 01/01/70 00:00 | |
| they do make p-channel logic mosfets | 01/01/70 00:00 |