Patrick! U think u could make same circuit adding a mechanism to let buzzer beep continuously until resetting it...therefore adding a reset switch ! ???
how can we make the buzzer keep buzzing until it is reset the person can pass the beam quickly and you might not be sure you heard a beep and also the sound will probably make them run away
+BEES Gab I tried that but it gives me no more than 2 seconds. I would like it stay on for 20 or 30 seconds.I can use a DPDT Relay and make I stay on till reset, but like I said I would like it to stay on 30 seconds and then reset itself (without Arduino)
No that would require a capacitor, this is just a simple potential divider system with Vout being controlled by a ldr, the current going into the base gets amplified which helps get a better frequency for the buzzer at the collector
excuse me but im getting it in the reverse order!!! when the laser hits the LDR it lightly beeps if nothing is shone to the LDR there is just silence pls tell the solution
Replace buzzer with input if 555 time in monostable mode. Output from 555 drives the buzzer instead. The resistor and capacitor in the 555 will determine how long the buzzer stays on.
The technical explanation is not correct. An npn base to emitter juntion acts as a diode and will not allow the voltage to go to 4.5v as is mentioned in the video. It will stay at about 0.7..0.8v,. Instead of vbe to go to 4.5v, the base-emitter current will increase and active the npn.
Laser security system is my first experiment .this is a good experiment in Electronics.
Great video. Thanks a lot. How do we make this buzzer to stay on until a reset button is pressed?
Please advise
Awesome! Nice, clear and concise. Thanks for making it simple.Cheers,LD
Sooo good.Very clear and looks simple. Really useful...
Can we use a PNP transistor instead of a NPN transistor? If no, then pls explain the reason.
Yes you can buddy
Patrick!
U think u could make same circuit adding a mechanism to let buzzer beep continuously until resetting it...therefore adding a reset switch ! ???
Use an SCR which will stay on until grounded. Alarms are popular applications for SCRs.
You are using a laser... so what do safety curtains normally use?
I built the same circuit and unable to get it to work... Whats the amps on the power Supply?
One quick question, instead of using a laser, can we use LED's for it? just wondering.
yes of course, but laser is for big distance
LED produces a much weaker beam. A divergent beam.
how can we make the buzzer keep buzzing until it is reset the person can pass the beam quickly and you might not be sure you heard a beep and also the sound will probably make them run away
Nice vid, good explained and simple!
hi just want to ask if you have any tutorial how to make a simple remote controlled alarm. a simple on and off alarm. =)
Thanks Very Much bro. I made one with help of your video.
Can I use 2N2222A transistor by replacing the 2N2222 transistor??? Please help me...😌
can i have a look of how the 5v battery looks plss?
Partick, where I can buy the LDR 1K light -100K Dark? I have been looking on line but I have not found it yet. Is it ok if I use a LDR 5K-100k?
what LDR did you use ?
could you make a flip flop beeper with N2222A? ( beep-beep-beep instead of constant beeping?)
Brilliant just what I needed, thanks
how about if we make it continuous alarm what kind of transistor we need ??????? plssss answer
Hi Patrik Is there a way to make it stay on for a few seconds after the laser hits the LDR?Or is there a way to make it stay on, until a manual reset?
+dana miller add some 555 timer
+BEES Gab I tried that but it gives me no more than 2 seconds. I would like it stay on for 20 or 30 seconds.I can use a DPDT Relay and make I stay on till reset, but like I said I would like it to stay on 30 seconds and then reset itself (without Arduino)
why don't u add capasitor to regulator 7805 ?
Why don't you specify what caint of buzzer you are using active vs passive.
Any way to have the opposite, The buzzer silent and when the beam is broken, it will sound?
I think it is possible, try to move the BUZZER in serial with the LED receiver (LDR)
Use pnp transistor or interchange the LDR and the 10k resistor.
can I use 2N7000 transistor for the circuit?
pls reply soon
look at the datasheet of both to be sure
can i use bc547 transistor instead of 2n2222?
Sure you can, it is one of its equivalents, especially in this case
Whats the main principle ?
Is it RC series circuit?
No that would require a capacitor, this is just a simple potential divider system with Vout being controlled by a ldr, the current going into the base gets amplified which helps get a better frequency for the buzzer at the collector
thank you for sharing your knowledge.....
excuse me but im getting it in the reverse order!!! when the laser hits the LDR it lightly beeps if nothing is shone to the LDR there is just silence
pls tell the solution
mee too
It was your mistake in ldr or transtor
May i use BC547 transistor?
This is my 1st project in my college
Thanks for the great video
Great. Love you, bro.
Can I use a photo diode instead of LDR? If yes then how??
Abhiti Sachdeva both are same...
can i put a PNP transistor instead of NPN?
How to convert to 12v
How to add 555 timer
i love u you r a genius
dont't ........ shut up u fool
how to keep the alarm beeping for a few seconds?
Replace buzzer with input if 555 time in monostable mode. Output from 555 drives the buzzer instead. The resistor and capacitor in the 555 will determine how long the buzzer stays on.
hy ,can any body plz tell me how to shield LDR from stray light?
Put it in darkness place
I am tried this but didn't work
very thnxxx
the greatest results that I have had was by using the Gregs Electro Blog (just google it) without a doubt the most useful course i've followed.
The technical explanation is not correct. An npn base to emitter juntion acts as a diode and will not allow the voltage to go to 4.5v as is mentioned in the video. It will stay at about 0.7..0.8v,. Instead of vbe to go to 4.5v, the base-emitter current will increase and active the npn.