| ??? 11/29/05 12:22 Read: times |
#104340 - This could be the reason... Responding to: ???'s previous message |
J Cena said:
I have used 74HC244 at the output of channel A of magnetic pulse generator as output voltage is only 0.4V. This could be the reason for malfunction. Try to use a comparator (e.g. 1/2 LM393) with hysteresis (5mV is enough) and adjustable threshold. At output a LED should be driven, which detects low state. Change now very slowly the threshold from 0V to 5V and look whether the output toggles. By this you can determine the low level and high level of output signal of your magnetic sensor. Now, alter condition of your motor, means change rpm, look whether low and high level of signal will change (should not relevantly). After that procedure, adjust the threshold level to be exactly in the middle of determined low level and high level, remove the LED, connect instead a 4k7 pull-up and connect the output to your micro. Kai |
| Topic | Author | Date |
| C2051 & Magnetic pulse generator | 01/01/70 00:00 | |
| either i or o | 01/01/70 00:00 | |
| hmmm..but | 01/01/70 00:00 | |
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| This could be the reason... | 01/01/70 00:00 | |
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| why the UG? | 01/01/70 00:00 | |
| pc scopes | 01/01/70 00:00 | |
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| What tells the oscilloscope? | 01/01/70 00:00 | |
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| Excessive rise times during startup? | 01/01/70 00:00 | |
| Good, but even better would be | 01/01/70 00:00 | |
| Full story | 01/01/70 00:00 | |
| thanks, so can I... | 01/01/70 00:00 | |
| yes, if and only if the channel A | 01/01/70 00:00 | |
| cheerz | 01/01/70 00:00 | |
| Time bomb.. | 01/01/70 00:00 | |
| Perhaps a little explanation? | 01/01/70 00:00 | |
| setting the hysteresis | 01/01/70 00:00 | |
Thank, Erik! | 01/01/70 00:00 |