# 24VDC for arduino and also 12V and 24V pumps **URL:** \ **Category:** General Guidance\ **Created:** [August 28, 2023, 8:12am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701 "2023-08-28T08:12:57Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 28, 2023, 8:12am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/1 "2023-08-28T08:12:57Z")
I am using 4 24V pumps and 1 12V pump. I am thinking to use a 5V relay and a 24VDC power source because I only want single power source. Can I just use a buck converter for both 12V pump and Arduino to use them with 24V, connect other pumps directly to 24V and connect relays to arduino(Thinking of using 8 channel 5v relay driver). And is it a big problem to power relays from Arduino, if it is what should I do for this case? Thanks for any advice. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [August 28, 2023, 9:14am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/2 "2023-08-28T09:14:34Z")
Hi, @ysfblkn Welcome to the forum. What model Arduino are you going to use? If you want to use a 24V supply, then DC-DC convert to 12V then DC-DC convert to 5V, then it is quite plausible. If you use a 8 channel 5V relay unit, then it will take care of the drive current for the relays from the low control current of the controller. You will need to do a basic diagram and add up all the 24V, 12V and 5V load currents to find the size of the 24V supply and the DC-DC converters in your system. Can you please tell us what your project is? Tom... 😀 👍 ☕ 🇦🇺 ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 28, 2023, 9:29am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/3 "2023-08-28T09:29:01Z")
Hi Tom, Thanks so much for your reply. It is just a simple mixing device, also I do not think to run any of the pumps together so I will just choose the power according to one of the pumps maximum use. I am using an Arduino Leonardo. And do you mean that I do not have to use a separate power source for relays and I can power them directly from Arduino? ---
**Author:** ![Railroader](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/railroader/32/274550_2.png) [@Railroader](https://forum.arduino.cc/u/Railroader)\ **Post date:** [August 28, 2023, 10:00am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/4 "2023-08-28T10:00:24Z")
You don't power relays from any controller pin. They are designed for such currents. Power should come from the buck converters. ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 28, 2023, 10:27am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/5 "2023-08-28T10:27:53Z")
Sorry I could not understand what you mean. There are only 2 buck converters, 1. between power source and arduino, 2. before 12V pump. ---
**Author:** ![Railroader](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/railroader/32/274550_2.png) [@Railroader](https://forum.arduino.cc/u/Railroader)\ **Post date:** [August 28, 2023, 10:57am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/6 "2023-08-28T10:57:09Z")
What is it You don't understand? Which reply? ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 28, 2023, 11:17am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/7 "2023-08-28T11:17:38Z")
I am planning to use Arduinos 5V output to control relays, but I did not understand what you mean by > [@Railroader](#): > > Power should come from the buck converters. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [August 28, 2023, 11:23am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/8 "2023-08-28T11:23:19Z")
> [@ysfblkn](#): > > And is it a big problem to power relays from Arduino, if it is what should I do for this case? Thanks for any advice. Yes it is a big problem. If you use 5V relays then you will need another buck to convert the 24V to 5V for the relays Why don't you use 12V relays? ---
**Author:** ![Railroader](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/railroader/32/274550_2.png) [@Railroader](https://forum.arduino.cc/u/Railroader)\ **Post date:** [August 28, 2023, 11:35am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/9 "2023-08-28T11:35:47Z")
Power the 5 volt relays and the controller from a 24 to 5 volt buck converter. Power the 12 volt motor from a 24 to 12 volt buck converter. ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 28, 2023, 12:17pm UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/10 "2023-08-28T12:17:07Z")
But I can still use arduino to control relays while powering relays from another source right? And what is the difference between using 5v or 12v relays in this situation? I thought using 5v because I wantes to connect relay module directly to arduino ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [August 28, 2023, 4:12pm UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/11 "2023-08-28T16:12:51Z")
It depends on the relay module you buy. With some, the relay coils can be powered by 12V but the control signals can be 5V ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [August 28, 2023, 11:09pm UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/12 "2023-08-28T23:09:12Z")
> [@jim-p](#): > > Yes it is a big problem. If you use 5V relays then you will need another buck to convert the 24V to 5V for the relays > Why don't you use 12V relays? Agreed! Those little blue (SPST) relays have a coil power of about 360mW, 72mA @ 5V, only 30mA @ 12V. 72mA is a big load for the Arduino's 5V power supply, but with 12V relay modules the Arduino only has to supply 2~3mA for each relay's opto coupler or switching transistor. ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 29, 2023, 4:41am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/13 "2023-08-29T04:41:50Z")
Thanks for your reply. I power relay module from a different power source. Arduino only will control the relays. Is this still apply in this situation as well(Arduino having too much load)? Also can Arduino control 12v relays? ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [August 29, 2023, 4:50am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/14 "2023-08-29T04:50:19Z")
If you have a separate power supply for the relay coils, you should be OK. For future reference, modules like yours are available with 12V relays that are still triggered by a 5V optocoupler from Arduino. Of course, you would need a 12V supply for the relay module. [12V relay module](https://www.amazon.com/sspa/click?ie=UTF8&spc=MTo4MzQzNzgzMDYwMjY2NjA1OjE2OTMyODQ2NTI6c3BfYXRmOjIwMDAxNDYzOTg2NDQxMTo6MDo6&url=%2FHiLetgo-Channel-OPTO-Isolated-Support-Trigger%2Fdp%2FB00LW2GM84%2Fref%3Dsr_1_1_sspa%3Fcrid%3D2T6VP5HN8LL3T%26keywords%3D12v%2Brelay%2Bmodule%26qid%3D1693284652%26sprefix%3D12V%2Brelay%252Caps%252C457%26sr%3D8-1-spons%26sp_csd%3Dd2lkZ2V0TmFtZT1zcF9hdGY%26psc%3D1) ---
**Author:** ![ysfblkn](https://avatars.discourse-cdn.com/v4/letter/y/3d9bf3/32.png) [@ysfblkn](https://forum.arduino.cc/u/ysfblkn)\ **Post date:** [August 29, 2023, 4:56am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/15 "2023-08-29T04:56:54Z")
If I use 12v relays, would I still need to power relays from a separate power source, or would it solve the risk for Arduino when relays are directly powered from Arduino ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [August 29, 2023, 5:42am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/16 "2023-08-29T05:42:49Z")
Well, you already have a 12V supply for pumps, you also have 24V available. 2 12V relays would only require about 60mA, 2 24V, about 30mA. [24V relay module](https://www.amazon.com/sspa/click?ie=UTF8&spc=MTo2MDQ0NjgwMDIwNDMwNjA1OjE2OTMyODc4MjI6c3Bfc2VhcmNoX3RoZW1hdGljOjIwMDA0MTU3NzUxMDc5ODo6MDo6&url=%2FHiLetgo-Channel-OPTO-Isolated-Trigger-Arduino%2Fdp%2FB09TYKWHPV%2Fref%3Dsxin_16_pa_sp_search_thematic_sspa%3Fcontent-id%3Damzn1.sym.1c86ab1a-a73c-4131-85f1-15bd92ae152d%253Aamzn1.sym.1c86ab1a-a73c-4131-85f1-15bd92ae152d%26crid%3D2F6ZQIFZCDP6G%26cv_ct_cx%3D24V%2Brelay%2Bmodule%26keywords%3D24V%2Brelay%2Bmodule%26pd_rd_i%3DB09TYKWHPV%26pd_rd_r%3De51d3555-0934-4fe7-925e-e0b387d5f648%26pd_rd_w%3DKPOrU%26pd_rd_wg%3DhFXnn%26pf_rd_p%3D1c86ab1a-a73c-4131-85f1-15bd92ae152d%26pf_rd_r%3DN67Q4XDX8703QA9V2CQ6%26qid%3D1693287822%26sbo%3DRZvfv%252F%252FHxDF%252BO5021pAnSA%253D%253D%26sprefix%3D24v%2Brelay%2Bmodule%252Caps%252C918%26sr%3D1-1-364cf978-ce2a-480a-9bb0-bdb96faa0f61-spons%26sp_csd%3Dd2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM%26psc%3D1) ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [August 29, 2023, 7:17am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/17 "2023-08-29T07:17:23Z")
Hi, Lets put it in a diagram. One suggestion, feel free to edit. ![image](https://europe1.discourse-cdn.com/arduino/original/4X/8/2/1/8213f387712eaf0e45f58c8a8cfa83e8c81f56f9.png) Tom.... 😀 👍 ☕ 🇦🇺 ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [August 29, 2023, 8:38am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/18 "2023-08-29T08:38:30Z")
Yea verily. 😃 ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [August 29, 2023, 9:43am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/19 "2023-08-29T09:43:07Z")
> [@ysfblkn](#): > > If I use 12v relays, would I still need to power relays from a separate power source No, you can use the same power supply ---
**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:** [February 25, 2024, 9:44am UTC](https://forum.arduino.cc/t/24vdc-for-arduino-and-also-12v-and-24v-pumps/1162701/20 "2024-02-25T09:44:00Z")
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