| ??? 12/24/05 14:17 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#105887 - Answers Responding to: ???'s previous message |
Nikhil said:
1. I got undefined response in my digital ckt using 8051 when i switch load like fan or computer in my room. First, you must find out, where the noise enters your circuit. For this you will need an oscilloscope. Even a very cheap and slow one would help, I guess. Look, at what point of circuit something strange happens, if you turn-on the fan. In many cases the 5V regulator doesn't get enough voltage at input, for instance because input storage cap is too small, or transformer output is too low, or current drawn is too high for transformer. Another reason for such problems can be grounding errors: You should have a ground star point at 0V pin of your 5V regulator. Whatever you connect to your digital circuit, each signal ground should always be connected to this ground star point. Nikhil said:
2. In my other project which is battery operated (6V,9V,12V) but i want 5v for my ckt. my voltage regulator 7805 itself is eating 3.2mA. This is not so much compared with what the microcontroller circuit draws. Only remedy is to choose ultra low current consuming components for the microcontroller circuit, or to use a bigger battery. Kai |
| Topic | Author | Date |
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| Answers | 01/01/70 00:00 | |
| thank u kai i am already having | 01/01/70 00:00 | |
| Further questions | 01/01/70 00:00 | |
| The often overlooked fact is that "power | 01/01/70 00:00 | |
| i have used 3300uf storage cap | 01/01/70 00:00 | |
| posts in gobbelygook | 01/01/70 00:00 | |
| i was not aware | 01/01/70 00:00 | |
| why should I try to decipher what you | 01/01/70 00:00 | |
| capacitor postions | 01/01/70 00:00 | |
you need 10-100nF directly (less | 01/01/70 00:00 | |
| It's the neglectin of solid ground plane | 01/01/70 00:00 | |
| thank you kai i will try with solid gnd | 01/01/70 00:00 | |
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