Hall effect sensor circuit. I have a need to produce a simple liquid flow LED Display

[AlanRoger]

My need is simple≥ Battery operated flow device using a hall effect linear output unit. Output to couple to 8 to 10 LEDs so that the greater the flow the greater number of LEDs light up. Has anyone a basic circuit design I could start with please

 

[Nigel Goodwin]

You mean an ammeter? - you just want to monitor the current?.

Probably the simplest option would be an Arduino, and there are plenty of examples out there.

 

[AlanRoger]

No not current flow but Liquid in a pipe using an immersed small magnet and a Hall effect sensor mounted on the out side pipe wall. . They are very small flows like 30 cc per minute . It will be vertical and the internal magnet will rise up about 30 mm as the liquid flow increases.

 

[Nigel Goodwin]

Again, Arduino, or any micro-controller - read the analogue input, and drive the LED's accordingly.

 

[Les Jones]

I don't think a hall effect sensor will give a linear output with the magnet moving over a distance of 30 mm.
Can you post the datasheet on the hall device. (Or a link to it.)

Les.

 

[ZipZapOuch]

I've seen a small cone-shaped insert (cast nylon) with a strong magnet inside. The cone fits in a pvc pipe and a sensor measures its position above "bottom".

 

[DHolub]

My need is simple≥ Battery operated flow device using a hall effect linear output unit. Output to couple to 8 to 10 LEDs so that the greater the flow the greater number of LEDs light up. Has anyone a basic circuit design I could start with please

As a Consulting Engineer, I was contracted to design and produce prototypes for this exact thing over 30 years ago by a company in Wisconsin. I did it all amd turned over the prototypes and schematics, per contract, to the companies engineering department. I don't know if the company is still around anymore, but you can try looking up Hedland Engineering in Wisconsin. By now, I'm sure you can purchase this type of flow sensor rate off-the-shelf.
All the best,
Don