| ??? 02/14/06 14:14 Read: times |
#109946 - Fire risk Responding to: ???'s previous message |
Oliver said:
I forgot to mention that you should have some protective components around the LED because spikes will shoot straight through the cap. It's what they invented transzorbs for. Transzorbs cannot solve all problems. The mess of these caps in series with mains is, that if bursts or surges are arriving from mains all eventual current limiting components are heavily overstressed. This means, that current limiting parts must be designed with lots of headroom, making them big and costly again. Another issue is that such circuits using caps in series with mains do always suffer from relevant fire risk, because there's no limit for excessive voltage spikes on mains guaranteed. Using a mains transformer for this task is much safer, because these parts are designed to withstand voltages of several thousands of volts. Kai |
| Topic | Author | Date |
| monitoring mains voltage | 01/01/70 00:00 | |
| Opto with capacitor | 01/01/70 00:00 | |
| re opto with cap | 01/01/70 00:00 | |
| Some protective components required | 01/01/70 00:00 | |
| Fire risk | 01/01/70 00:00 | |
| Transformer | 01/01/70 00:00 | |
| thats the best chioce | 01/01/70 00:00 | |
| There's nothing wrong | 01/01/70 00:00 | |
| Space | 01/01/70 00:00 | |
| please do not go aargh | 01/01/70 00:00 | |
| Opto isolator = LDR + Neon? | 01/01/70 00:00 | |
| 10mA? | 01/01/70 00:00 | |
| Hmmm | 01/01/70 00:00 | |
| Why not... | 01/01/70 00:00 | |
| Neon + Photodiode | 01/01/70 00:00 | |
| Loosing brightness | 01/01/70 00:00 | |
| Transformer isolation is needed! | 01/01/70 00:00 | |
| Previously, on 8052.com | 01/01/70 00:00 | |
| Safety first | 01/01/70 00:00 | |
| Transformer | 01/01/70 00:00 | |
| Sorry | 01/01/70 00:00 | |
| two places to look | 01/01/70 00:00 | |
| Annoying, isn't it?! | 01/01/70 00:00 | |
| Thanx! | 01/01/70 00:00 | |
| maybe Amveco 6200 series? | 01/01/70 00:00 | |
| Transformers | 01/01/70 00:00 | |
| Could also be used | 01/01/70 00:00 | |
| an Idea | 01/01/70 00:00 | |
| The simplest ideas are the best | 01/01/70 00:00 | |
| Poor dads | 01/01/70 00:00 | |
| Tainted food | 01/01/70 00:00 | |
| Yes, but... | 01/01/70 00:00 | |
| Low current | 01/01/70 00:00 | |
Exactly! | 01/01/70 00:00 |