Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

How to reset this ic without any switch....

Status
Not open for further replies.
Thanks for reply but friend is there any way to test whether the timer is working or not just for an idea .... because we cant wait 3hr to check whether the timer is working or not....
 
The LEDs attached to R1 and R2 will flash (slowly) to indicate that the timer is running. The R2 LED flash rate should be 0.3793 Hz for a 3hr timer.

Note: C3 should be either a 4.7uF non-polarised electrolytic, or 2 x 10uF polarised electrolytics connected back-to-back (as shown at the bottom of the schematic).
 
Last edited:
As you now want to have a variable timed period I've modified the circuit so that it can be set anywhere in the range ~1.5 - 7.5 hrs just by adjusting variable resistor R4.
Note that in the new circuit (attached) :-
a) R4 is now 250k, R3 is 68k.
b) Pins 5 and 6 of the CD4093 are now separated and are connected respectively to pins 2 and 1 of the CD4060 so that the beeper pulses coming from the alarm clock are blocked for 3/4 of the timed period, i.e. for at least the 1 hr that they persist. That enables periods down to ~1.5 hrs to be timed.
c) The relay is now driven from the Q14 output (pin 3) of the CD4060.

As an indication that the timer is working, the R2 LED, driven by pin 9 of the CD4060, flashes at a rate ~ 137/T, where the rate is flashes per minute and T is the period in hours. [The R1 LED flashes at 1/16 that rate].
 

Attachments

  • Reset6.gif
    Reset6.gif
    28.9 KB · Views: 134
Thanks for you help... and friend so I hope that as I want it will work.....
Again ...
I want as the clock beeper pulses comes it will reset the ic and the total delay as I want for eg: 1 + 2 = 3 hour..
here 1 hour is for alarm clock and 2 hour is the timing in timer... so total after 3 hour relay is driven.......

and we can set the timing by adjusting R4..

And friend suppose that for eg :
alarm clock beeps for 30 minutes .... and I have set the R4 to 1 hour timing....
So.. alarm clock + timer = 30 minutes + 1 hr = 1 hr and 30 minutes... so the relay is driven after 1 hr 30 minutes....
Is this right as I said above friend....
 
Last edited:
alarm clock beeps for 30 minutes .... and I have set the R4 to 1 hour timing...
You told us the alarm sounds for 1hr (not 30mins). My circuit was designed accordingly. With the component values shown the minimum timer period is ~1.5hrs, as I mentioned in post #43. That means the timer is started (reset) by the first pulse in the beep and stops after a minimum of ~1.5hrs.
Note that the relay drive part of the circuit apparently needs to be changed. As it stands, while the timer is running the relay is de-energised and at the end of the timed period the relay is energised. I assume you want the opposite?
 
Last edited:
Friend my alarm sounds of 1 hr.. I have just gaven an example of 30 minutes.. So you said this circuit was design for minimum 1.5 hr.. I agree ... But in any other alarm clock the time of beeper can vary.. Suppose 20 minutes.. Or etc.. So what components we should set to gain any alarm clock.. Beeper time..
 
If you want to use the circuit with an alarm clock which beeps for less than 1hr then you can reduce the value of R3 (currently 68k). That will enable you to set timer periods shorter than ~1.5hrs. The guiding principle is that the beep duration must be less than 0.75 * T, where T is the timed period. [If the duration is > 0.75 T then the timer will be re-triggered as soon as the timed period expires; which isn't what you want].

Edit: Did you take note of my comment about the relay drive ?
 
Last edited:
A revised circuit showing the changed relay drive is attached. Note the transistor is now a pnp type (e.g. 2N2905) and the relay coil connection is between its collector and ground.
 

Attachments

  • Reset7.gif
    Reset7.gif
    28.7 KB · Views: 131
Thanks friend.... I will check it and if any problem occur I will let you know....
thanks again ... for helping me,,,
 
HEllo alec...

I have tested voltage on the beeper of my alarm clock..
and the result I have posted in my attachment.. in zip file...

There is a video and an audio.

The video is of the voltages which was appearing on the beeper while
testing with multimeter and with sound disturbance I have added beeper audio separate which my alarm sounds..

For clarification I have added both of this..

So, friend Please have a look... and suggest whether your circuit will
work with it or not....

Thanks in advance...
 

Attachments

  • my files.zip
    1 MB · Views: 90
I'm afraid the files aren't helpful. I can't tell from the video what voltage range your meter is set to, or whether it's AC or DC.
Try connecting the signal via a series silicon diode to a 0.22 uF (or greater) capacitor to rectify and smooth the signal, measure the voltage across the cap using the meter on its 2V DC range (or nearest DC range you have), and let us know the reading.
 
hi.... alec....

I dont have 2v dc range instead i have 20 dc range.. so I set the multimeter in 20 volt dc range and I checked the voltage on the beeper tips and I got the voltage to varying from 0.08 to 0.25..
It was varying according to the beeper ... for eg : As I touched the the beeper contacts the voltage starts from 0.08 then 0.10 then 0.15.... , 0.20 , 0.10... and this voltages was repeating till the beeper was beeping...
and In my video you can see the voltages is varying on the meter...
I am using 20 v dc range...

Kindly .... help ?
 
Were those voltages measured using the setup shown in the video, or using the diode + capacitor as I suggested in post #51? That suggested method should give a steadier reading.
 
Hi alec..
Do you mean I should check like this....
please look in my attachment...
 

Attachments

  • Beeper.png
    Beeper.png
    3.4 KB · Views: 116
No. Like the attached.
You may have to swap over the two wires at the left side of the pic, depending on your beeper polariity, so that you get a reading.
 

Attachments

  • BeepMeter.png
    BeepMeter.png
    14.7 KB · Views: 120
hello alec....

OK ! I have tested as per in your attachment...... .
But the result was same friend... it was showing varying voltage...
/??
 
Last edited:
Well if you are getting up to .2V across the cap then the beeper voltage must be about .2 + .6 = .8V, which should be plenty to provide the required timer-start pulses. Good luck with the build.
 
Thanks friend but first I want to test 3 hr timer separate...
And if I am satisfied with my 3 hr timer then I will add the alarm clock...

So friend please modify the 3 hr timer circuit alone with Led in the place of relay....
and the delay for vew minutes for just testing whether this timer is working or not... If I successful build this small delay then I will move to 3 hr delay...

I want to move step by step because I am new in electronic... ...
so please... help...

and thanks for you for helping me up-till here... ?
 
Just leave out the relay and temporarily use 0.22uF for C3 instead of 4.7uF. That will speed up the timer by ~ 20 times. The circuit already has LEDs to indicate the timer is working. Re-read my earlier posts.
 
Hello friend...

I have made a circuit diagram and I have replace led in place of relay... as per you told..

so should I arrange like this as in this circuit.....

so please have a look in my attachment .....

and if any problem occur then please correct it... I dont have 250 k ohms pot so I have used 500 k pot...

and what is the meaning of this you have told in back post.. I didn't understand properly :

[[[[[[[[
As an indication that the timer is working, the R2 LED, driven by pin 9 of the CD4060, flashes at a rate ~ 137/T, where the rate is flashes per minute and T is the period in hours. [The R1 LED flashes at 1/16 that rate].
]]]]]]]]]

please explain in simple form... friend..

thanks..
 

Attachments

  • reset.gif
    reset.gif
    24.2 KB · Views: 120
Last edited:
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top