Hi guys and girls,
I've been googling for weeks and going crazy trying to teach myself this stuff, but I simply don't have the brain capacity or the patience to find what I'm looking for - so I'm hoping someone out there will find this simple to the point of stupid and can help me out
I'm trying to monitor a circuit of a set resistance, say 100ohms. If the circuit goes above or below this value, then the monitoring device will supply a 12v output (to a warning light). It's basically an alarm circuit that will run off a 12v SLA battery.
I have looked into using a basic comparator as the switching component, 100ohm in and 100ohm on the other/monitoring side - change the value by say +/- 10% and it switches an output. Unfortunately I don't know enough about them to know if they can switch when open circuited on one side, rather than sensing a change of voltage (needing that PD to switch like a relay). Is this the easiest way to do it, with the least components? Or can I use a transistor somehow?
I'd greatly appreciate any help or suggestions on a simple way of making this circuit effective and using the least amount of power as possible. I don't mind if the output, once triggered, switches a relay and draws more power, I just need to work out the switching side of things for now.
Thanks again
Dirk
I've been googling for weeks and going crazy trying to teach myself this stuff, but I simply don't have the brain capacity or the patience to find what I'm looking for - so I'm hoping someone out there will find this simple to the point of stupid and can help me out
I'm trying to monitor a circuit of a set resistance, say 100ohms. If the circuit goes above or below this value, then the monitoring device will supply a 12v output (to a warning light). It's basically an alarm circuit that will run off a 12v SLA battery.
I have looked into using a basic comparator as the switching component, 100ohm in and 100ohm on the other/monitoring side - change the value by say +/- 10% and it switches an output. Unfortunately I don't know enough about them to know if they can switch when open circuited on one side, rather than sensing a change of voltage (needing that PD to switch like a relay). Is this the easiest way to do it, with the least components? Or can I use a transistor somehow?
I'd greatly appreciate any help or suggestions on a simple way of making this circuit effective and using the least amount of power as possible. I don't mind if the output, once triggered, switches a relay and draws more power, I just need to work out the switching side of things for now.
Thanks again
Dirk