The Yocto-PowerRelay is a USB relay: it contains a USB-driven SPDT relay switch: you can drive by software the relay input to one of the two outputs. To make it easier to test your project, two leds positioned on each side of the connector show the output currently active.

This device only includes a single relay, but it can drive higher loads than the Yocto-Relay device. The relay and the connector can stand a current of 5A. Be aware that using a relay to drive inductive loads (motors, transformers) may lead to accelerated aging of the relay. Please refer to the documentation for hints on reducing this type of problems.

This product is replaced by the Yocto-PowerRelay-V2, which is almost identical but features a reinforced insolation and a higher withholding voltage. Caution, A and B outputs are swapped on the terminal block of the Yocto-PowerRelay-V2 !

This device can be connected directly to an Ethernet network using a YoctoHub-Ethernet, to a WiFi network using a YoctoHub-Wireless-n and to a GSM network using a YoctoHub-GSM.

Yocto-PowerRelay Yocto-PowerRelay Yocto-PowerRelay

USB cables and enclosures to be ordered separately.

This product is not available anymore. It has been replaced by the Yocto-PowerRelay-V2


Product name:Yocto-PowerRelay
Replacement product:Yocto-PowerRelay-V2
USB connector:micro-B
Max switching current:5A
Max switching power:1250W
Max withholding voltage:400V DC
Normal operating temperature:5...40░C
Extended operating temperature1:-30...85░C
Supported Operating Systems:Windows (PC + IoT), Linux (Intel + ARM), macOS, Android
Drivers:Driverless, no driver needed
API / SDK / Libraries:C++ Obj-C C# VB.NET UWP Delphi Python Java Android LabVIEW
API / SDK / Libraries (TCP only):Javascript Node.js PHP
RoHS compliance:RoHS III (2011/65/UE+2015/863)
Suggested enclosure:YoctoBox-Short-Thick-Black
Harmonized tariff code:9032.9000
Made in:Switzerland

1 The extended temperature range is defined based on components specifications and has been tested during a limited duration (1h). When using the device in harsh environments for a long period of time, we strongly advise to run extensive tests before going to production.

Accessories and related products

YoctoBox-Short-Thick-Black, Enclosure for Yoctopuce device (short, thick, black)Micro-USB-Hub-V2, Micro USB hub (multi-TT) with solder pads, for DIY useFix-2.5mm, screws and spacersUSB-A-MicroB-50, USB 2.0 type A to Micro-B data cable, 50 cmYoctoHub-Ethernet, Ethernet-enabled hub for Yoctopuce modules

Related articles and application examples


User manual (HTML)
User manual (PDF)
3D file (STEP)
RoHS certificate
Most recent firmware51180 (12/02/2022)
Programming libraries61813 (07/05/2024)
Command line API61813 (07/05/2024)
VirtualHub application61813 (07/05/2024)

Add a comment 19 comments

1 - funky81 Wednesday,april 17,2013 12H49

Hi, supposed I want to buy for of these.
Is it possible to connect each of them by using usb powered hub, 4 port for example?
Looking forward for your answer.


2 - martinm (Yocto-Team)Wednesday,april 17,2013 12H58

Sure, our devices are regular USB devices, they work with USB hubs.

3 - omnibane Wednesday,july 10,2013 2H22

Hi. Just wondering. As I live in Australia, the main voltage is 240V. The specifications stated the max voltage as 220V. Will the relay be able to handle it?


4 - martinm (Yocto-Team)Thursday,july 11,2013 4H59

@omnibane: the relay itself is rated up to 250 V AC and the connector is rated 300V AC, no problem, it will work. We rated the device at 220V because it's the voltage we have here in Europe and because we systematically keep a security margin with our product specs.

5 - michael Sunday,november 24,2013 10H39

Hi. Can you confirm please RoHS / CE compliance of the product? As declaration, official letter or something like?

6 - mvuilleu (Yocto-Team)Monday,november 25,2013 6H53

@michael: RoHS compliance is officially announced on each product page, as well as on the product documentation, but on request to support we can write a letter of compliance if you need. We only use RoHS components in our products, and use exclusively lead-free solder paste (KOKI SB6N58-M500SI). We would not be allowed to sell our products if they were not RoHS, as Switzerland has integrated the UE RoHS regulation into its laws (ORRChim 05/2009).

As for CE marking, the situation is different: as the electronic boards we sell are semi-finished goods part of a product assembly, they are not CE-marked. CE compliance of a product assembly cannot be "inherited" from the certification of its parts, a product assembly can only be assessed for CE compliance as a whole. To give an example, if you integrate our Power-Relay into a box that uses it to switch a 24V solenoid, the directive on "Low Voltage Electrical Equipment" would not apply (because it is below 50V). But if you use it to switch 230V, then your assembly must comply with this directive, in particular to prevent electric shocks. Obviously a Yocto-PowerRelay hanging on wires would not be compliant, but if you put it in an adequate enclosure it becomes compliant.

7 - minipci1321 Thursday,june 26,2014 10H09

Hi, french electric regulation require simultaneous cut out on both L and N. Are you planning any such product? If not (or not in the near future) -- is there an easy way to pair two of these devices to achieve simultaneous action using only one USB connection?

8 - mvuilleu (Yocto-Team)Thursday,june 26,2014 10H48

@minipci1321: In this case, one solution is to use the scheme described in http://www.yoctopuce.com/EN/article/how-to-switch-high-power-devices-from-usb : use the Yocto-PowerRelay (or a Yocto-MaxiCoupler) to drive external high-power 220V relays.

9 - uoygnivol Saturday,july 12,2014 11H38


May I use these devices with Arduino board?


10 - martinm (Yocto-Team)Saturday,july 12,2014 12H52

@uoygnivol: our devices require a USB port in Host mode to work. So no, it will not work with an Arduino board. You should look for an Arduino Relay Shield.

11 - vikmak Tuesday,october 21,2014 10H23


I work for an IT company with over 160,000 employees, we are the second largest IT company in India.
we have a requirement to switch off the light and fan at a workstation when occupant is not there at its seat. I am exploring an option of doing this through USB port of Laptop/desktop the person is using at the workstation. For ex. when the PC/laptop goes to a sleep mode, the USB port switches off the light and fan also. Can a product like Yocto- power relay do this for us?

please let me know.


12 - al.acoustic Sunday,september 20,2015 17H26

Hi, The PC Doesn't recognize the RELAYHI1 after connecting,. The PC is running Windows-10 and I have tried all USB ports and it is the same situation. Please help resolve this I have a deadline for a project submission.


13 - mvuilleu (Yocto-Team)Monday,september 21,2015 6H29

@al.acoustics: the reason can be many different things, starting from a bad USB cable (power cable instead of data cable) to improperly powered USB hub. We will followup with you by e-mail to diagnose your problem.

14 - ravi Friday,september 25,2015 1H05

Question regarding triggering DC 12 V/0.6 Amp electronic lock.

We need to trigger a DC 12 V/0.6 Amp electronic lock. Would that work with this relay? Please let me know.

Lock details are available at http://www.amazon.com/gp/product/B012KISKU6

15 - mvuilleu (Yocto-Team)Friday,september 25,2015 5H48

@ravi: yes, it will work, but aware that when you disconnect an inductive load with a relay you will cause a significant voltage surge that may cause both EMI and early relay aging. To prevent interferences from EMI, make sure the cables going from the relay to the lock and lock power supply are well separated from other electronics, and if needed shield them. To reduce both EMI and early relay aging, you can add a multilayer varistor such as AVX VA200060K121 in parallel to the lock coil: this will absorb the transient voltage at the source.

16 - eipa Thursday,january 28,2016 19H37

I've found an error in the example script of the python library for the PowerRelay. In /Examples/Doc-GettingStarted-Yocto-PowerRelay/helloworld.py line 37 currently is:
" relay = YRelay.FindRelay(target)"
but it should be:
" relay = YRelay.FindRelay(target + '.relay1')"
for it to work.

17 - martinm (Yocto-Team)Friday,january 29,2016 7H51

@eipa: Thank you for the report, the fix will be available with the next Yocto-API release.

18 - gedl Saturday,may 14,2016 18H52


I am getting this dmesg output when connecting to Linux (4.2.0-36-generic #41-Ubuntu SMP Mon Apr 18 15:49:10 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux)

May 14 19:03:17 grace kernel: [341270.672955] usb 1-4.2: new full-speed USB device number 8 using xhci_hcd
May 14 19:03:17 grace kernel: [341270.745699] usb 1-4.2: Device not responding to setup address.
May 14 19:03:17 grace kernel: [341270.970285] usb 1-4.2: New USB device found, idVendor=24e0, idProduct=000d
May 14 19:03:17 grace kernel: [341270.970298] usb 1-4.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
May 14 19:03:17 grace kernel: [341270.970306] usb 1-4.2: Product: Yocto-PowerRelay
May 14 19:03:17 grace kernel: [341270.970313] usb 1-4.2: Manufacturer: Yoctopuce
May 14 19:03:17 grace kernel: [341270.970320] usb 1-4.2: SerialNumber: RELAYHI1-64F0D
May 14 19:03:17 grace kernel: [341270.971952] usb 1-4.2: can't set config #1, error -32

Am I missing somehting? I am also unable to use the device in MacOS El Capitan and WIndows 7

19 - martinm (Yocto-Team)Saturday,may 14,2016 19H45

@gedl : Each Yoctopuce USB device is tested before packaging, so there are good chances the relay is OK. Did you check the USB cable? What are the VirtualHub logs? When you plug the relay with the button pressed, and look at the virtualHub main page ( do you see it as a device waiting to be flashed ?

Yoctopuce, get your stuff connected.