Hi everyone! I have made a very simple device that uses a digital panel milliameter that measures a dc current. Is there any milliameter on the market that has a built-in timer on it's screen, that starts counting when the measuring current is above a standard value, let's say 18 mA? If there is not any gadget like this on the market, how could I place a digital timer in my circuit that can do this job? In specific, I would like to place a small digital timer that will start counting at the exact moment the current measured by the milliameter reaches the 18mA. I hope I made myself clear. Thank you very much.

 

Hi everyone! I have made a very simple device that uses a digital panel milliameter that measures a dc current. Is there any milliameter on the market that has a built-in timer on it's screen, that starts counting when the measuring current is above a standard value, let's say 18 mA? If there is not any gadget like this on the market, how could I place a digital timer in my circuit that can do this job? In specific, I would like to place a small digital timer that will start counting at the exact moment the current measured by the milliameter reaches the 18mA. I hope I made myself clear. Thank you very much.

You need to flesh out your specs some more. What happens after the current reaches 18 mA and the timer starts? Does it keep just keep counting up forever (rolling over, at some point)? What happens if the current falls back below 18 mA? When/how does the timer get reset?

There are a lot of timer modules on the market that are electronically controlled/gated. You just need to be able to create a trigger event at your 18 mA threshold. The fact that you are already measuring the current in question should make this pretty straightforward, particularly if you have appropriate DC power available to power a small circuit.

There are also options using things like Arduinos or other similar technologies in which the hardware aspects would probably be very simple, but you would need to learn how to write some pretty basic code and be able to program the device.

 

The timer starts counting whenever the current reaches 18mA and continues to count as long as the current is greater than this value. Every time the current drops below 18mA the timer should automatically reset, and start measuring again only each time the current is greater than or equal to 18mA. I do have appropriate DC power available to power a small circuit. I just dont know what is available on the market and how to achieve it. Thank you for your answer.

 

The timer starts counting whenever the current reaches 18mA and continues to count as long as the current is greater than this value. Every time the current drops below 18mA the timer should automatically reset, and start measuring again only each time the current is greater than or equal to 18mA. I do have appropriate DC power available to power a small circuit. I just dont know what is available on the market and how to achieve it. Thank you for your answer.

OK, based on this functional description, a very simple time counter would satisfy the requirement simply by switching it on and off at the preset current level. There are such meters available to switch at a given display point. The ones that I have used most recently came from the "RED LION" company. And if they do not also sell a time counter that would match the appearance of the meter, other suppliers will certainly available.
I am trying to imagine a useful application for such a system that resets every time, and I do not come up with an application.