| ??? 07/06/05 06:39 Read: times |
#96658 - So where is the problem? Responding to: ???'s previous message |
If I am to understand what the problem is correctly - you have a comparator (lm324) to detect 800mV. This only works when you touch the pcb. But you haven't given us a drawing of this comparator but rather the whole controller. If I was to gaze into my magic 8 ball and ask it "would this work?" it would probably say "not likely". Am I right to assume the problem is with the comparator circuit? If it is, have you designed such that you have some hysteresis? Without some hysteresis, you could breath on it and have it oscillate. Are you limiting the input frequency? It may be acting as an antenna and picking up the local bollywood channel and causing the comparator to oscillate. Localise your problem and try to isolate potential causes of your problem. If you think the problem is coming through the power wiring - run your circuit off a battery. If this makes no difference we can rule out interference through the mains. Only after doing some investigation do you have some evidence. Without this we are just guessing. |
| Topic | Author | Date |
| is it ground bounce | 01/01/70 00:00 | |
| No, hum or high frequency instability | 01/01/70 00:00 | |
| high frequency | 01/01/70 00:00 | |
| plastic enclosure | 01/01/70 00:00 | |
| Spray nickel | 01/01/70 00:00 | |
| nice idea | 01/01/70 00:00 | |
| cost vs working | 01/01/70 00:00 | |
| Then use internal shielding | 01/01/70 00:00 | |
| internal shielding | 01/01/70 00:00 | |
| Schematic, plan of whole setup? | 01/01/70 00:00 | |
| hi kai | 01/01/70 00:00 | |
| So where is the problem? | 01/01/70 00:00 | |
Then, good luck... | 01/01/70 00:00 | |
| Nickel paint | 01/01/70 00:00 | |
| Ground bounce | 01/01/70 00:00 | |
| and next week | 01/01/70 00:00 |