Motion sensor, light-related circuit!!!

[duduelove]

Hi. In need of help.

My motion sensor is able to detect motion and does create voltage change. From 1.5V to 2.9V approx. Thus i used a Volt Comparator (339). I connect in 2V to a (-) input while i connect the sensor's output to (+) input to the (339). After which i connect the output to a (556) timer's trigger input. But while experimenting so, i found out that my timer's output is opposite.

Please help me solve this problem of mine, thank you very much!

 

[wp100]

Hi,

Your lm339 circuit is producing a High output , the 555 Trigger requires a Low.

Swapping your Lm339 + and - inputs should produce the Low output which triggers the 555 and produces the High pulse.

You do not say how long you want the 555 to time for, but if you are not using all the amps in the Lm339 then you can use one of them to create a simple monostable delay of up to a minute.

 

[duduelove]

Firstly, thank you for your advices.

The voltage comparator (339) outputs are 4.7V and 0.3V for high and low respectively. The timer is set for 3 seconds 'On' upon triggered. The timer (556) is able to be triggered after inputing a ground to trigger. But when i input the comparator's output to the trigger of the timer (556), is it unable to react upon the change in voltages (4.7V & 0.3V).

Any suggestions for it ?

Added after 3 minutes:

Firstly, thank you for your advices.

The voltage comparator (339) outputs are 4.7V and 0.3V for high and low respectively. The timer is set for 3 seconds 'On' upon triggered. The timer (556) is able to be triggered after inputing a ground to trigger. But when i input the comparator's output to the trigger of the timer (556), is it unable to react upon the change in voltages (4.7V & 0.3V).

Any suggestions for it ?

 

[wp100]

Hi,

Can you post your circuit - particularly the 339 to 556 connections / components.

 

[garv]

hi to all,
i am working on motion sensor project and in need of help now.....here i am attaching the circuit, plz lemme knw the connection of coil and diode in circuit coz i could not understand wat is it and why it is done for??....plz help me out and also tel me whether it is possible to make this circuit work with dc supply if yes than plz help me with simplified circuit to work with dc supply...thank u...

 

[kapilp]

@ garv ... the 'coil' in your circuit is actually a part of the relay (look above the coil for specs) alongwith the 2 switches. The diode is used as a 'freewheel diode'. The relay 'turns on' the triac and the CFL ... study the individual parts .... will help a lot as this is a very simple circuit.

 

[pranam77]

hi to all,
i am working on motion sensor project and in need of help now.....here i am attaching the circuit, plz lemme knw the connection of coil and diode in circuit coz i could not understand wat is it and why it is done for??....plz help me out and also tel me whether it is possible to make this circuit work with dc supply if yes than plz help me with simplified circuit to work with dc supply...thank u...

The said circuit was published in EFY magazine recently. The coil is the relay and there are 6diodes. 4 diodes work as rectifier which will convert AC to DC and one Zener diode will regulate the volatge to 12 volts as it is rated to, and D5 is a free wheeling for the relay coil.
Cheers

 

[garv]

hey dear kapilp and pranam,
thanks for your reply and efforts. i understood some things as you said but as i m new to this field so its getting difficult for me to understand lil' and circuit making or components working so i needed a simplified circuit which i can grab easily and understand its working. As i wanted it to represent in my college for final year so have very lil' time to work on it and go deeply. So it would be a nice gesture from you if you can help me with a circuit diagram to work with dc supply and also coil connection that is shown in the circuit below coz i tried but i didnt get anything instead of getting 3.3v at the base of transistor 2n2219 thats it. So plz help me with the coil connection with pin details.Hope to have a positive response.thanks

 

[pcsandhya82]

Hi,

In this circuit, the MT1 and gate will be shorted if the relay turns on. isnt this a flaw? also, the transistor in the path of relay. is that stable? how can we improve this circuit?

Regards,
Sandhya.