water tank level controller with atmega328p

[gsingh11]

hi, i am making a college project to control water in a tank with atmega328p. i have a problem relating to providing power to my device. I need 2 dc voltages 5v and 12v. Im using LM7805 and LM7812 to step down from 18v. I need to solution to decrease the heat dissipated.

[pcprogrammer]

Welcome to the forum.

Instead of linear regulators you could consider using buck converters. Should work fine for a simple MCU based project.

For instance something like these:
https://www.instructables.com/How-to-Use-DC-to-DC-Buck-Converter-LM2596/
https://nl.aliexpress.com/item/1005004272385130.html

[gsingh11]

thank you so much for your reply. That was helpful. I had 1 more question can you tell me a good dc water pump that has a high flow rate that can run in both directions.

[pcprogrammer]

Sorry, can't help you there, not my field of expertise.

[Siwastaja]

If your pumps are running from 12V and you are using a linear regulator to step down 18V for the pumps, no wonder you are having problems with heat dissipation. Consider switch mode converter (even a crappy ebay module) for 12V. You can still use 7805 to further reduce the 12V for the MCU if (I'm guessing) the 5V circuitry pulls only a tiny bit of current (MCU itself, a few mA).

EDIT: moved the answer to another of your questions to your other thread ( https://www.eevblog.com/forum/beginners/need-dc-water-pump/ )

[bidrohini]

This arrangement looks simpler to me: https://circuitdiagrams.in/water-tank-level-controller-using-arduino/

[MathWizard]

A lot of household cable boxes and modem's run off 12V/ 2A or 5A PSU's. Probably a lot of printers too. If they would have no problem with the motors, it shouldn't be hard to find some of those.

Linear 78xx regulators are ok for small currents, but not when you have to drop a bunch of overhead voltage like from 18v to 12V. If you add power resistors, that can help drop the voltage, loose the power as heat.

[beanflying]

thank you so much for your reply. That was helpful. I had 1 more question can you tell me a good dc water pump that has a high flow rate that can run in both directions.

In my former life 

You will need to use a positive displacement pump to be able to pump in and out. There is a few exceptions to this, pumps that have internal check valves (non return valves) as part of their mechanisms such as a typical Piston Pump or most diaphragm pumps cannot generally be reversed.

So this sees you looking for flexible impeller (Jabsco or Johnson as examples), Gear Pumps (generally two meshing gears), Lobe Pumps (generally sanitary or heavy industrial so skip these on cost), Peristaltic (hose pumps) generally suited to lower flows but might suit a mockup for school, Helical Rotor Pumps (Mono or Netzsch as brand examples) finally Vane Pumps and providing you can find one to suit one of the more affordable options.

As they are positive displacement types you also need to generally add relief valves to stop them blowing the plumbing or themselves up 

Worth a read https://dienerprecisionpumps.com/positive-displacement-pumps/ and do a little more Googling for additional info or ask some more.

[cantata.tech]

I had 1 more question can you tell me a good dc water pump that has a high flow rate that can run in both directions.

Do you have access to a 3D printer ? If so then you could probably print your own.

This guy on YT has some entertaining if not useful video ideas: https://www.youtube.com/@LetsPrintYT

Now, if you want some files to print straight away to get started, here are some on thingiverse https://www.thingiverse.com/search?q=water+pump