| ??? 02/14/06 17:42 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#109965 - an Idea Responding to: ???'s previous message |
Per Guldmann said:
Hey Forum.
I am doing a monitoring aplication: If mains power is cut off, an alarm of some sort is needed. Verry simple - a few resistors and an optocoupler, and here we go. The problem is, that if I want - say 10 mA - through my optodevice, then ill have a power disipation of about 2,3W (mains voltage is 230V AC). With aprox. 20 circuits to monitor, ill have some 46W to get rid of. So, is there any body out there having an idea, how to monitor mains power with low loss? For safety reasons ill prefer isolation! Per Why not use normally closed realy contacts for the alarm and have the coil 220VAC, as long as the mains is on the relay is energized making the alarm open circuit, if the mains goes off, the battery operated alarm starts wining. You can solve your problems and add simplicity to the design. Mahmood |
| 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 |