circuit to turn off a 9v device after X seconds. - Page 1
Forum section: electronics / beginners

author: wblackledg
author_rank: Regular Contributor
timestamp: April 28, 2015, 01:52:56 pm
content: I'm working on my continuing sump pump backup system.I the backup failure/high water alarm working.my wife (the boss) jumped in and said the alarm can only go so long until it shuts off. she worries if we aren't home it will drive the cat and dogs nuts. (probably right).Can somebody point me to an IC / circuit to cut off voltage after X number of seconds of voltage to the piezo buzzer?Also, is this a good time/excuse to pick up a microcrontroller programmer and program the chip to allow it to run for 30 seconds, then come back to life every 15 minutes for 15 seconds or something?thanks.

author: littlebill
author_rank: Regular Contributor
timestamp: April 28, 2015, 01:59:19 pm
content: thats kewl, im using a arduino for a sump controller im building as well, sure makes life easy, if you want to have it internet based, a raspberry pi is also a good choice!

author: wblackledg
author_rank: Regular Contributor
timestamp: April 28, 2015, 02:05:50 pm
content: Quote from: littlebill on April 28, 2015, 01:59:19 pmI do, but that will be version 3.0..Version 1.0 was the backup system from Home Depot. It sucked. The battery tester only tested one of six battery cells, so 5 could be bad but you wouldn't know it.Version 2.0 is what I'm working on now. I'm using a large bilge pump (Rule 1500), marine deep cycle batteries in parallel. (244 amp hours). I found a few circuits on ebay and an IC to test water levels for backup alarms. redundancy. Which is what brings us to this problem. the buzzer is the backup alarm, in case the backup pump fails.

author: chibiace
author_rank: Regular Contributor
timestamp: April 28, 2015, 02:10:08 pm
content: 555 timer?

author: wblackledg
author_rank: Regular Contributor
timestamp: April 28, 2015, 02:11:22 pm
content: Quote from: chibiace on April 28, 2015, 02:10:08 pmmy first thought. do you have an example of a circuit where it is used to turn off after x seconds/minutes. (I'm a software guy, not a hardware guy)thanks in advance.

author: littlebill
author_rank: Regular Contributor
timestamp: April 28, 2015, 02:12:00 pm
content: battery tester?are you talking about water level in the battery? or the actually capacity? because short of putting a load on the battery you will never be able to tell the battery's true capacity, without a load test.were you designing a SG test? or just surface voltage test?http://www.sumppumpsdirect.com/Basement-Watchdog-SPD-BW4000KIT-Sump-Pump/p2474.htmlis what i am using at my mothers, although i am building the controller for my buddy

author: wblackledg
author_rank: Regular Contributor
timestamp: April 28, 2015, 02:15:40 pm
content: Quote from: littlebill on April 28, 2015, 02:12:00 pmboth. first the home depot watchdog system only tested one cell of the battery.I am now using a floating charger with desulfinator. The water level I'm checking is the sump itself so I know when to kick the bilge pump on and off. the circuit comes from china via ebay. They use it for low water levels for a pump on their solar hot water heaters. I'm just reversing the logic.(to kick on when I have high water and kick off after the water is off both sensors).I had the low price version of this. but all in my version 2.0 is coming at about $350. Including the batteries.