# Why our 2 pump working at the same time **URL:** \ **Category:** General Guidance\ **Created:** [February 16, 2024, 11:48pm UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890 "2024-02-16T23:48:56Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![thky\_12345](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/thky_12345/32/1044483_2.png) [@thky\_12345](https://forum.arduino.cc/u/thky_12345)\ **Post date:** [February 16, 2024, 11:48pm UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/1 "2024-02-16T23:48:57Z")
Hi we are a students and our project is water dispenser with soap dispenser, we are using 9v to arduino uno r3. When we ON the arduino the sensor can sense then the water pump is working well however after 3 attempt it's not working well. The water in pump would flow continuously, that's our concern. Why it's not working well after the 3rd attempt? Also when our water pump is working the soap pump is also working, it's should not be like that, it's should work if the sensor has sense something. ---
**Author:** ![mancera1979](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/mancera1979/32/732001_2.png) [@mancera1979](https://forum.arduino.cc/u/mancera1979)\ **Post date:** [February 16, 2024, 11:56pm UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/2 "2024-02-16T23:56:33Z")
> [@thky\_12345](#): > > we are using 9v Is this a 9V battery? You have to use a power supply for the pumps, and for any motors for that matter. Post a diagram showing How everything is wired. A picture of a hand-drawn schematic will work. And then post your code according to the forum rules… ---
**Author:** ![thky\_12345](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/thky_12345/32/1044483_2.png) [@thky\_12345](https://forum.arduino.cc/u/thky_12345)\ **Post date:** [February 17, 2024, 12:01am UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/3 "2024-02-17T00:01:13Z")
![Schematic Diagram 2](https://europe1.discourse-cdn.com/arduino/original/4X/4/b/e/4be71eeff8e507dfaec7fa9d5c26339a35d3a501.jpeg) the sanitizer is not included, and we're not using 12v in arduino because it's not available at the moment we also don't have 5v in pump, would it work if don't have power source in pump? ---
**Author:** ![Ron\_Blain](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ron_blain/32/1126393_2.png) [@Ron\_Blain](https://forum.arduino.cc/u/Ron_Blain)\ **Post date:** [February 17, 2024, 12:02am UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/4 "2024-02-17T00:02:03Z")
Go back to the beginning of project guidance. [Now read this](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/681308) and other things you should have read before posting. Gee maybe the problem is in the code you failed to post or maybe the schematic you failed to post? Ron ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [February 17, 2024, 12:05am UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/5 "2024-02-17T00:05:52Z")
- Do not power the relays with the arduino 5v power pin. - There should be kickback diodes across the pumps. * * * In the Arduino IDE, use Ctrl T or CMD T to format your code then copy the **complete sketch**. Use the **\< CODE / \>** icon from the ‘posting menu’ to attach the copied sketch. ---
**Author:** ![thky\_12345](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/thky_12345/32/1044483_2.png) [@thky\_12345](https://forum.arduino.cc/u/thky_12345)\ **Post date:** [February 17, 2024, 12:15am UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/6 "2024-02-17T00:15:53Z")
can you explain more details, I'm sorry I'm only a highschool student and I don't know anything about this ---
**Author:** ![LarryD](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/larryd/32/215550_2.png) [@LarryD](https://forum.arduino.cc/u/LarryD)\ **Post date:** [February 17, 2024, 12:33am UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/7 "2024-02-17T00:33:49Z")
- The 5v pin on the Arduino should never be used to power relay modules. - Inductive loads, like your pumps, should have a reverse biased kickback diode across the coil. Read this discussion: > [@Flyback diodes and why you need them](https://forum.arduino.cc/t/flyback-diodes-and-why-you-need-them/675409): > > Any component that relies on an electromagnet or coil of wire for its operation will be inductive, that is the nature of coils of wire. Common examples are relays, solenoid and most types of motor. It is standard practice to put a 'flyback' diode across any inductive load in order to catch the back emf from the inductor when the current is interrupted. This requirement is usually taken at face value without being backed up by any kind of test results or evidence. This tutorial provides the evid… ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [February 17, 2024, 2:12pm UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/8 "2024-02-17T14:12:25Z")
You should use two dedicated power supplies (maybe three). Use one power supply for the Arduino (in this image, "12vdc") and at least one external power supply for peripheral devices - sensors, relays and pumps (in this image, "5vdc"). If needed, use two 5vdc power supplies for peripheral devices - one power supply for sensors and relays, the second power supply for pumps. ![punps](https://europe1.discourse-cdn.com/arduino/original/4X/f/d/b/fdbc38ff93531a86f93247e47160aa0ad7e01693.gif) ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [August 15, 2024, 2:13pm UTC](https://forum.arduino.cc/t/why-our-2-pump-working-at-the-same-time/1224890/9 "2024-08-15T14:13:05Z")
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