| ??? 04/27/06 14:51 Read: times |
#115116 - Exactly. Its what iam trying ... Responding to: ???'s previous message |
Russell said:
I gather you have a circuit that is working but you're trying to understand how it actually works at an engineering level. Exactly. Its what iam trying to do. Since this could help me use the components properly for my design (but i also concentrate on how well it is designed). Russell said:
I would suggest you read the datasheets carefully and break down the circuit into 'building blocks'. Yes Russell. I indeed got some information from the datasheets of the intended components. But for that LF412(U4A) i could not find the output source current rating. This holds me from analysing OPA 547 which forms a current amplifier. Russell said:
From looking at the circuit, we have a DAC (current output I'm assuming) then we have U4a which looks like the current to voltage conveter (refer to the dac datasheet). At closer inspection, it seems that U14 is used to hold a constant current through the coil, this current is set by the voltage from the DAC circuit. The current is sensed across a resistor and the voltage across the resistor is fed through the pga into the a/d. At a guess, this may be used to measure the sensitivity of the unit under test. The polarity to the coil can be reversed via the relay - maybe to test the sensitivity in both directions? Then there's the mosfet connected to the 8254 - to provide a test frequency? Maybe related to speed testing the unit under test? I'm not an expert on testing relays, so I really can't comment. Russell, Thanks for your efforts in giving me your analysis about the circuit. This is what i too could get when went through the design. But i dont think this type of understanding would help me work on it or modify it for some changes. In general, iam trying to get information on how to work with the signals while developing a circuit. Now, refering to this circuit, i could analyse to some extent but struck up with some which i have posted. Thanks, Suresh. |
| Topic | Author | Date |
| Circuit Analysis | 01/01/70 00:00 | |
| it might be easier to help if we knew | 01/01/70 00:00 | |
| Reply | 01/01/70 00:00 | |
| last time | 01/01/70 00:00 | |
| I second that | 01/01/70 00:00 | |
| Erik, This is not the only work iam carr | 01/01/70 00:00 | |
| comments | 01/01/70 00:00 | |
| It amazes me | 01/01/70 00:00 | |
| old soldiers never die | 01/01/70 00:00 | |
| Sorry, mine has an electron gun! | 01/01/70 00:00 | |
| son of a(n electronic) gun | 01/01/70 00:00 | |
| Exactly. Its what iam trying ... | 01/01/70 00:00 | |
| HUH? | 01/01/70 00:00 | |
| LM412 source current for a particular .. | 01/01/70 00:00 | |
| Zilch | 01/01/70 00:00 | |
| The basics..... | 01/01/70 00:00 | |
| Reply to :comments | 01/01/70 00:00 | |
| Reverse engeering?? | 01/01/70 00:00 | |
| Let me give all the informations i have | 01/01/70 00:00 | |
| Well, I wasted my time then! | 01/01/70 00:00 | |
| Faulty design? | 01/01/70 00:00 | |
| Thanks and few more.... | 01/01/70 00:00 | |
| Please! | 01/01/70 00:00 | |
| reply | 01/01/70 00:00 | |
| When "inheriting" a complex design, you | 01/01/70 00:00 | |
and sometimes ... | 01/01/70 00:00 |