| ??? 07/14/05 15:30 Read: times |
#97382 - Thermal shut-down? Responding to: ???'s previous message |
Karim said:
I`ve build a voltage supply for an at89c2051 programer. The output should be 12 and 5V to program the chip.
Some measures with the multimeter between + and ground gave me 12.3V and 4.7V. 12V input voltage for your 78L05 is a bit high, especially if relevant load currents are flowing. Then your tiny 78L05 heats up and the internal thermal shut-down gets invoked. So, try a lower input voltage, or another regulator type, like 7805, for instance. Kai |
| Topic | Author | Date |
| 4.7 V for at89c2051 programmer..enough? | 01/01/70 00:00 | |
| 4.7 V? | 01/01/70 00:00 | |
| load? | 01/01/70 00:00 | |
| Rise, not fall... | 01/01/70 00:00 | |
| oscillating | 01/01/70 00:00 | |
| that is the problem and still those with | 01/01/70 00:00 | |
| 79XX are even more weird | 01/01/70 00:00 | |
| 79xx - same with me | 01/01/70 00:00 | |
oscillation | 01/01/70 00:00 | |
| Thermal shut-down? | 01/01/70 00:00 | |
| get 4.91V now !! | 01/01/70 00:00 | |
| 4.91 V | 01/01/70 00:00 | |
| diode | 01/01/70 00:00 |