Im newbie with electronic components but is there like a timer component for an electric circuit which like you can control how long current is allowed to flow?

Okay im trying to make what my uncle did in high school he made a buzz bomb where you used resisters and capiciters in a series to make a timer connected to a buzzer a switch and a battery. I have a 4m ohm resister and a 15 uf capiciter.

http://www.elecfree.com/electronic/wp-content/uploads/2007/11/lm555powerdelay.gif

Using either of the top two circuits, how do I make a shut off timer? I Built the second one and it works perfectly but with my design I don’t want any power flowing. So when the relay activates to shut down it’s own power supply all it will do is reset itself and turn into an oscillator, right?

How do I do this so that the power stays off.

Thanks,
Jake

http://www.elecfree.com/electronic/wp-content/uploads/2007/11/lm555powerdelay.gif

Using either of the top two circuits, how do I make a shut off timer? I Built the second one and it works perfectly but with my design I don’t want any power flowing. So when the relay activates to shut down it’s own power supply all it will do is reset itself and turn into an oscillator, right?

How do I do this so that the power stays off.

Thanks,
Jake

Hey, i am a fire alarm lover. My control panel is homeade using a 160 in one electronic kit. I have 1 bell and strobe, 3 pull boxes.

I have a latchning circuit created using a relay. But i want to create a delay circuit. (All pull boxes work with the latching circuit)

I have been told to use a 555 timer but at this time i dont have a breadboard or the timer. I herd i could use a capaciter and resister, but cant figure out how to wire it up.

I have capacicters, resisters, transisters, diodes etc.. all on the board (kit) i can use.

What i want is to have it so when any of the intiating devices are activated such as pull stations, it has a 1-3 second delay before the relay actives and then activates the alarm.

Anybody that knows how to help me would be greatly appreciated.

Thanks so much, Chris.

i have to some project for this subject..but still didnt know which topic is better..my lecturer ask me to build a simple circuit/system that will make use at least one of these electronic elements -

Op-amp
Feedback system
Voltage regulator
Oscillator
555 Timer
Power amplifier

the project must include this criteria
1)Introduction/Abstract
2)Objective
3)List of the components used
4)Circuit ( graphic diagram or block diagram)
5)Explanation of the system (circuit operation)
6)Results (calculations, simulations and etc.)
7)Discussion & Conclusion
8)References

so,i just need an idea which topic is better and where the link that i can refer to..all your kindness will appreciate..thanks..

Hey, i am a fire alarm lover. My control panel is homeade using a 160 in one electronic kit. I have 1 bell and strobe, 3 pull boxes.

I have a latchning circuit created using a relay. But i want to create a delay circuit. (All pull boxes work with the latching circuit)

I have been told to use a 555 timer but at this time i dont have a breadboard or the timer. I herd i could use a capaciter and resister, but cant figure out how to wire it up.

I have capacicters, resisters, transisters, diodes etc.. all on the board (kit) i can use.

What i want is to have it so when any of the intiating devices are activated such as pull stations, it has a 1-3 second delay before the relay actives and then activates the alarm.

Anybody that knows how to help me would be greatly appreciated.

Thanks so much, Chris.

it's a side by side. i can't turn the defrost timer like you could on the older refrigerators. How do i get the box to go into defrost? With an electronic board? The defrost timer is located in the back near the compressor. I use to be able to use a screw driver to turn my manual defrost timer into the defrost mode. I was told once to unplug it and wait for so many seconds and turn it back on! But I forgot.. Please help.
it's self defrosting. I'm trying to diagnose why it's not working properly?
it's self defrosting. I'm trying to diagnose why it's not working properly?

Model # 110.77694100 76941. Ser. # M70904 502. Very old Sears (70s) but uses circuit board instead of mechanical timer. FSK printed on circuit board. We fix electronics here but have run out of luck with this. Simple electronics with one IC, and three transistors that drive three non latching relays that are separate from board. Need part but especially circuit board diagram. IC and transistors are house marked and are hard to guess. Ic is 12 or 14 pin DIP marked AMI in Korea. It even has a neon bulb on the board.

The purpose of the timer is to make single shot weapons fire automatically. you can find the original electronic schematic
here > http://forums.xbox-scene.com/index.php?showtopic=643928

it allows for approx 7 shots in 0.5 or 0.6 of a second.
this is incredibly fast and works well.
however there are many people that are using this tlc 555 and picaxe chips. and it is time for me to mod the mod.

the goal here is how to make it shoot faster to the brink of what the game will allow. ( which should be one trigger pull and the entire magazine is gone)

I have tried using 2 circuits in one controller this has the same effect as just using one.
I believe that the capacitors play a role in the frequency of repetition. but i have very basic knowledge of these kinds of things
there are 2 different caps in the circuit a 1uf and a 100pf one is ceramic one is a tantulum I don't know which controls the rate.
please if you have any info or knowledge in this area It would really help.
running them in series didn't work it remained the same speed I do really appreciatet he input however
thanks again
thank you