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LCD random characters, Frequency issue on generator

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trm33

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i made a system for generator which starts with RF remote and stops the generator automatically, the system is made with atmega8 and an LCD is also connected which shows Voltage and Frequency of generator. the problem i m facing is that when the circuit is near the generator the voltage varies rapidly and shows wrong frequency, and if same circuit is used away from the generator but on same generator voltage, it shows all the things OK. and another problem when during self start LCD shows some other invalid characters.

anyone help to solve filter design

Regards
 

did you put adequate filters in the power line for atmega board?
 

Show the circuit and also the code. Also show the PCB layout.
 

srizbf said:
did you put adequate filters in the power line for atmega board?
Click to expand...

i m not using any EMI filter at AC level, using step down transformer and diode bridge +capacitor to measure Ac voltage and same transformer is used for frequency measurement before diode bridge, frequency and voltage both are working ok on mains AC supply and even on generator supply if the system is away. i m sending some pics which i made
https://obrazki.elektroda.pl/3892860100_1440589684.jpg
https://obrazki.elektroda.pl/5658508100_1440589686.jpg
https://obrazki.elektroda.pl/3210568200_1440589688.jpg
https://obrazki.elektroda.pl/7350953500_1440589689.jpg
https://obrazki.elektroda.pl/6996272900_1440589690.jpg
https://obrazki.elektroda.pl/6829771900_1440589692.jpg
 
Last edited:

Since you have a working sytem that malfunctions at certain distance , what is required is "dressing" for your setup.

The photos show the protype which needs a rearrangement of all hanging wires.( but all system under development will be like yours :lol:)

One thing that you can test is:

those two lines (one you take from trfr for voltage measurement and another for frequency) can be re arranged such that it doesnt pickup any noise from external sources.

carefully route that two wires and its ground to atmega input port lines , probably with shield.

and see that your dc supply has adequate filters.

if it works then , you can go to further steps.

please test and report.
 

srizbf said:
Since you have a working sytem that malfunctions at certain distance , what is required is "dressing" for your setup.

The photos show the protype which needs a rearrangement of all hanging wires.( but all system under development will be like yours :lol:)

One thing that you can test is:

those two lines (one you take from trfr for voltage measurement and another for frequency) can be re arranged such that it doesnt pickup any noise from external sources.

carefully route that two wires and its ground to atmega input port lines , probably with shield.

and see that your dc supply has adequate filters.

if it works then , you can go to further steps.

please test and report.
Click to expand...
ok i will re-check then i will inform u, however main changeover relay is already removed from the system now this box only have self starting mechanism,,
 

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