Hi group,
+12v | NC | | |, .-. | IN -+--------,-=B4-------( X )-+ | =B4| | '-' | | | | | |NO .-----. | +---| |--+------| |--+ | | | | '-----' | | | RELAY | | T | | | --- | | +---o o--+ | | | (created by AACircuit v1.28.6 beta 04/19/05I have the above ladder diagram consisting a relay, a buzzer and a push button switch.
I would like to sound the buzzer "x" when the input is low and when the button is pressed the relay would be switched on and holds itself through the "NO" contact and the buzzer is switched off due to the "NC" contact is opened. Both the NO and NC contacts belong to the same relay. When the input goes high, the relay releases and the circuit goes back to normal waiting for the next alarm.
I would like to convert this into a circuit using cmos chips. I use an AND and inverters and a 4013 FF and came out with the circuit below.
VCC VCC + .-. | ALARM=3DL | |10K .-----. NORM=3DH | | | |BUZZER '-' '-----' IN|\\ | _4081 | -| >O---+-------| \\ __4081 | |/ | | | )------| \\ ___ |/ | +--|__/ | )--|___|--| VCC | +-----+ +---|__/ 10K |> |+ | | | | | =3D=3D=3D | o | | | | /-\\ | PB |=3D| | | =3D=3D=3D | | o | | | GND | | | | | +-------------------+ | | | | .-----. .-. | =3D=3D=3D | +--|Q S D|-VCC | | | GND | | | /| | |10K | | |_ L | |\\ | +---| >O--+ |/ (created by AACircuit v1.28.6 beta 04/19/05
The C and R at the set input of the 4013 is a power-up set to make the Q output high during power on. The PB silences the buzzer until a new alarm is detected.
The circuit seems too complicated and I was cracking my head how to simply it. I would also like the 4013 to be toggled by both H to L as well as L to H transitions. How should I do it?
Is there any simpler way to do it? Any help very much appreciated.
Allen