Discussion in "Project Doubts" started by    LAMBO    Apr 12, 2018.
Thu Jun 21 2018, 02:13 PM
#21
hi sir
can we change the frequency on pin no 39 of IC at89s52 in oder to get desire frequency in output
i have a link related with mine project down below

https://drive.google.com/file/d/1iA7O6iQiUbyGgJPesdhbmCXT-H-KUuod/view?usp=drivesdk

Thu Jun 21 2018, 10:49 PM
#22
The frequency of the pulses has to be the same as mains, that is 50Hz.
What you want to change is the time between the start of the new cycle
and the pulse from pin 39.

From what I see the timing is way out.
I suspect the problem is with the signal on pin 12 ( P3.2.)
Without an oscilloscope it will be hard to test.

Connect a 1K resistor in series with a small loudspeaker. (transistor radio sized)
With long leads and crocodile clips it is a useful tester.

Disconnect the mains lamp.

Connect the speaker between pin 12 and ground.
Do you hear a faint buzz ?

Then connect the speaker between pin 39 and +5volts.
You should get a similar buzz, but the volume should vary
as you change the speed.


Mon Jun 25 2018, 02:19 PM
#23
hi sir
as per circuit diagram i have checked the frequency it was about 100hz at pin no 12 and the fan was rotating only at level 8 and otherwise it remains ideal

but sir i have manually changed the frequency at 25 hz on pin no 12 its working fine

link below
https://drive.google.com/file/d/1QHlfGgxy97DJIilmBq8vQgIsXruYwCoG/view?usp=drivesdk

sir can u let me know how can i change frequency at pin no 12 by changing program or hardware if yes then how???
Tue Jun 26 2018, 06:03 AM
#24
This kind of circuit will never be able to properly
control the speed of the motor/fan you have.
Use a light bulb for now.
Please repeat your test with the original connections to pin 12.
Monitor pin 12 and pin 39 on your oscilloscope to compare input and output.
I would set both channels to DC.
I look forward to seeing the video.

Wed Jun 27 2018, 05:23 AM
#25
hi sir
i have connected circuit originally as mentioned and sir i get frequency about 136-148 hz on pin no 12

yellow line is for pin 12 and blue is for pin 39 on osilloscope
link below
https://drive.google.com/file/d/19tLYL-dLw_rJuffduzZRSkjEqPLkuiuj/view?usp=drivesdk
Wed Jun 27 2018, 10:10 PM
#26
Interesting video.
>i get frequency about 136-148 hz on pin no 12

That is very odd it should be 100Hz (or 120 HZ if your local supply is 60Hz)
Can you check that again.
What power supply are you using ?

Are you sure the signal is actually reaching pin 12, is there any chance of a dry joint
on the socket ?
From the video it seems you only get a pulsed output on the top two settings
is that correct ?

There seems to be a lot of noise on the scope display.
This circuit has poor smoothing, which could cause the misfiring.
Add a 0.1uF ceramic and a 100uF (or bigger) electrolytic capacitor to the output of the
5 volt regulator.

Attached is some very simple test code.
It just copies the input on 12 to the outputs on pin 39 and 17
so all three should be the same.


[ Edited Wed Jun 27 2018, 10:16 PM ]
Fri Jun 29 2018, 09:15 AM
#27
hi sir
i have changed the input supply finally its giving me an 100-103 hz on pin no 12
but sir waves on oscilloscope of pin 39 comes only on 7 and 8 level of bar graph led
yellow line is for pin 12 and blue is for pin 39
link below
https://drive.google.com/file/d/1QSFZ9QhzZoClIW_olhRpOmjchegsdhEt/view?usp=drivesdk
Fri Jun 29 2018, 07:49 PM
#28
>i have changed the input supply
Do you mean you have added the capacitors I asked you to ?

Try the program I posted last time.
Sat Jun 30 2018, 02:58 PM
#29
hi sir
no sir i haven't connected any kind of capacitors instead of that i have changed the input power supply its giving me perfect 100hz on pin no 12
now do u want me to added capacitor ????? yes or no??

and sir i haven't tried the program yet now
Sat Jun 30 2018, 09:00 PM
#30
Yes, add a 0.1uF ceramic and a 100uF (or bigger) electrolytic capacitor to the output of the
5 volt regulator.

Get Social

Information

Powered by e107 Forum System

Conversation

Fri Aug 07 2020, 08:01 AM
Tony Eldredge
{{Are You interested|Interested|Would you be interested} in {advertising|an advertising service} that {costs|charges} less than {$50|$40|$49|$39} {per month|monthly|every month} and {delivers|sends} {hundreds|thousands|tons} of people who are ready to buy directly to your website? {Check out|Visit|Have a look at|For details visit}: http://www.getwebsitevisitors.xyz |{Looking for fresh buyers?|Want more visitors for your website?|Do you want more people to visit your website?} {Get|Receive} {hundreds|thousands|tons} {of people who are ready to buy sent directly to your website|of keyword targeted visitors directly to your site}. {Boost your profits|Boost revenues} {fast|quick|super fast}. Start seeing results in as little as 48 hours. {For more info|To get details|For additional information|To get info} {Check out|Visit|Have a look at}: http://www.getwebsitevisitors.xyz
Thu Jun 11 2020, 06:27 AM
anudee
sir could please send the code for I2C and wifi interfacing with 8051
scena
Tue May 19 2020, 10:29 PM
Does anyone have microcontroller programming software for STC15F104W (core 8051, 4 k, 128 byte, 6 I/O pin, UART ... DIL8), that works?
Sat May 02 2020, 07:38 PM
Tamu Gurung
Hi I am looking for a assembly language program for a digital decimal counter. Time counts max limit of 2 mins starting from 2.00 mins and ending at 0.00. time is to be displayed on 4 7-segment LED displays. Edsim51 simulator to be used. Thanks
Wed Mar 25 2020, 01:39 PM
Tajammul
Sir kindly send the code file i2c for 8051
ExperimenterUK
Fri Mar 13 2020, 10:36 PM
@ Rohitnani,ABEBE..which project ?
Fri Mar 13 2020, 12:55 PM
ABEBE
how can get hadwere of this project
Rohitnani
Sat Mar 07 2020, 05:11 PM
Sir, Could you please send me the zip file input password....
Wed Feb 26 2020, 04:58 PM
Peter Parker
Is it possible to send multiple messages using only 1 GSM module?
Sat Feb 01 2020, 10:12 AM
Pearl Olin
Hello,

Downloads

Comments

Mirza123
Thu Jun 25 2020, 03:46 PM
eunicelove124
Mon Jun 22 2020, 03:03 PM
cerouno
Tue Jun 16 2020, 05:10 PM
Marce
Sat Jun 13 2020, 09:43 PM
Davidthils
Thu May 21 2020, 12:44 PM
Jakeror
Thu May 21 2020, 01:28 AM
motorCar
Wed May 20 2020, 07:05 PM
Vordrync
Wed May 20 2020, 11:52 AM

Online

Guests: 118, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 38215
Newest member: Mirza123
Forum Activity
liqian Avatar
Posted By liqian
Fri Aug 07 2020, 03:31 AM
I found the part on here https://www.jotrin.com/pr...
ExperimenterUK Avatar
Posted By ExperimenterUK
Wed Jul 01 2020, 11:07 PM
PS: I am a new learner thats why my question may s...
Mirza123 Avatar
Posted By Mirza123
Wed Jul 01 2020, 02:05 PM
Thanks for the assistance. I have read the data sh...
ExperimenterUK Avatar
Posted By ExperimenterUK
Wed Jul 01 2020, 10:12 AM
See section 15 (Ports) of the data sheet. ...
wimac Avatar
Posted By wimac
Tue Jun 30 2020, 10:05 AM
How did you know that it is not 8051. Mirza123It i...
Mirza123 Avatar
Posted By Mirza123
Tue Jun 30 2020, 08:39 AM
It seems ports on the AT89LP2052 is not like on th...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Jun 30 2020, 08:34 AM
It seems ports on the AT89LP2052 are not like on t...
Mirza123 Avatar
Posted By Mirza123
Thu Jun 25 2020, 04:07 PM
Hello!i am trying to use AT89LP2052 ( AT89LP2052 h...
ExperimenterUK Avatar
Posted By ExperimenterUK
Wed Jun 17 2020, 09:42 PM
It is about capacitor? i should put it between Vcc...
cerouno Avatar
Posted By cerouno
Wed Jun 17 2020, 10:37 AM
Take another look at the power supply to the LCD.A...