1. kandyudayan@yahoo.com

    Thread Starter New Member

    Jan 7, 2011
    I have a read switch in water tank, which short when the water is full in the tank.
    Down below i have a busser connected with series with a battery, when ever the water is getting full
    it gives an alarm so that we used to switch off the motor manually. The problem is that the busser keep
    on giving alarm till the water level goes down, thus draining the battery also manually we are disconnecting the battery
    to stop alarm.

    Is there any solution to give alarm for 1 minute and alarm goes off even though the read switch is on. And get ready
    after 1 hrs for the next time when the tank is full.
    Is it possible to do with a PIC? if not possible with a circuit.
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    Would be easy to do with a capacitor-coupled input triggering a LM555 1-minute monostable. The monostable would be triggered when the tank switch closes, and the buzzer would sound for 1 minute. When the water level eventually drops, opening the switch, the alarm will be reset and ready to sound again.

    Use "Circuit 5" : http://home.cogeco.ca/~rpaisley4/LM555.html#4 Change the timing resistor and capacitor for a 1 minute high output. 220KΩ and 220uF will give ~50 seconds.

    Last edited: Jan 8, 2011
    kandyudayan@yahoo.com likes this.
  3. Leigh


    Feb 11, 2010
    And yes, a micro, pic or many others, could do this easily, but there is the overhead of having a programming environment set up, and being able to write the software. I have just enough of that to get by, so that is my preferred option. A micro for most simple to medium complexity applications would only cost a dollar or two. And I'd much rather write code than solder wires. On the other hand, LM555's will probably be around long after humanity has left the planet, and my favourite micro, etc, may not...