| ??? 10/01/10 18:41 Read: times |
#178833 - PC817 for isolation + driving relay? |
Hi freinds, I am making a industrial instrument and in that i want to drive a 12V relay. Isolation is required between the relay circuit and MCU circuit. The 12 VDC relay coil has 400ohm resistance [will require 30mA current]. I am thinking of driving the relay directly with of PC817. The PC817 datasheet tells that it can handle upto 50mA current at output. so i feel its ok to use PC817 alone for relay switching, without any more device between. But im little bit confused because many times i have seen people using the line drivers ULN2803, 2003, etc. they dont switch the relay directly from opto-isolator. Is there any technical reason ? or its ok to use PC817 to drive the relay? Have anybody used PC817 for any similar applications? Anita. |
| Topic | Author | Date |
| PC817 for isolation + driving relay? | 01/01/70 00:00 | |
| Why isolate relay coil? | 01/01/70 00:00 | |
| Re: | 01/01/70 00:00 | |
| Optos don't actually "isolate" from a EMC point-of-view... | 01/01/70 00:00 | |
| ......... | 01/01/70 00:00 | |
Star point grounding and filtering... | 01/01/70 00:00 | |
| PC817? | 01/01/70 00:00 | |
| Is LED current of 5mA is sufficient? | 01/01/70 00:00 | |
| no | 01/01/70 00:00 | |
| A darlington? | 01/01/70 00:00 | |
| SSR? | 01/01/70 00:00 | |
| RE: "book by Bosshcart " | 01/01/70 00:00 | |
| RE: "book by Bosshcart " - Link | 01/01/70 00:00 |