need help with a circuit build

[wozzzzza]

been out of electronics too long and ant work this one out now.
i want to build a circuit, an alarm circuit, that will toggle armed and unarmed with 2 separate high inputs, e.g. one input goes high for half a second to turn it on and another input goes high for half a second that turns it off. no matter how many times a high pulse is sent to the on input, the alarm will remain armed and vica versa.
another n/c input to trigger the alarm out for 5 seconds, so when this input is open circuit it will trigger the alarm output for 5 seconds only when the circuit is armed. after 5 seconds waits for another alarm input.
how can i build something like this easily??

 

[barry]

The arm/disarm function can be performed by s S/R latch. The alarm trigger can be a monostable.

 

[KlausST]

Hi,

I probably would use a small microcontroller. (maybe a 8 pin one is sufficient)
* less parts
* faster building the hardware
* flexible with modifications
* best accuracy
* small

but ... one needs to write the software. ... though it´s a simple task.

Klaus

 

[danadakk]

Sim[ple block coding of a micro, suggest Arduino Nano board. Or use 8 pin ATTINY85
(you would use a Nano board to program it).

This is a possible working example, but logically the off input I do not seem to understand. Is the off
pin to terminate an ongoing on alarm after the .5 sec ?

The above is mBlock, a free programming utility, you drag and drop the blocks to describe your
desired program, and mBlock converts it to C code used to program the board/chip.


Regards, Dana.

 

[BradtheRad]

Using a popular invert-gate oscillator I built an alternating beeper that you might be able to adapt. A hex inverter IC sounds sufficient. A slow oscillator enables and disables the fast oscillator. Each time you click the switch starts a sequence.

Link for above schematic. Click to:

1) Navigate to falstad.com/circuit,
2) Load my schematic into the animated interactive simulator,
3) Run it on your computer.

tinyurl.com/23f6624g

Use your mouse to click the switch open and closed.

 

[wozzzzza]

Hi,

I probably would use a small microcontroller. (maybe a 8 pin one is sufficient)

like suggested above Arduino Nano board. Or use 8 pin ATTINY85 ???

This is a possible working example, but logically the off input I do not seem to understand. Is the off
pin to terminate an ongoing on alarm after the .5 sec ?

Regards, Dana.

on pin to arm the alarm, off pin to disarm alarm e.g. car alarm, on to turn on, off to turn off and alarm will only trigger when armed and off will also turn off when triggered.

 

[danadakk]

This will sound alarm for min 5 sec, after than stay off until alarm off button pushed.

Regards, Dana

 

[wozzzzza]

This will sound alarm for min 5 sec, after than stay off until alarm off button pushed.

View attachment 194372


Regards, Dana

sweeet, i want to give this a go, what exactly do i need to make it happen? like what programmer what hardware etc...
thanks.

 

[KlausST]

like suggested above Arduino Nano board. Or use 8 pin ATTINY85 ???

yes.