• USD
  • EUR
  • AUD
  • BRL
  • GBP
  • BGN
  • CAD
  • CNY
  • HRK
  • CZK
  • DKK
  • HKD
  • HUF
  • INR
  • IDR
  • MYR
  • MXN
  • NZD
  • NOK
  • PHP
  • PLN
  • RON
  • RUB
  • SGD
  • ZAR
  • KRW
  • SEK
  • CHF
  • THB
  • TRY
  • JPY
  • AED
  • EGP
  • MDL
  • RSD
  • UAH
Welcome to our store!

Shopping Cart

0 items


Registered mail (Posts), table based cost.
DHL Express service, fixed cost at 42.00 USD per order.
DPD, fixed cost at 22.00 USD per order.


Credit Cards, we accept Visa, MasterCard, Maestro
Paypal, you can place the order directly via our web shop
Wire transfer, please contact with us for Proforma-Invoice

Verified by

website security

For EU Customers

All prices are WITHOUT VAT 20.00%

If you are located in EU and your company has valid VAT number we will reduce the VAT charge AFTER you make the order as our site does not support online VAT number validation. We do it as partial refund. You can use this online tool for VAT validation:

USB Four(4) Relay Output Module,Board for Home Automation

USB Four(4) Relay Output Module,Board for Home Automation

This is Four Channel relay board controlled by computer USB port. The usb relay board is with 4 SPDT relays rated up to 10A each. You may control devices 220V / 120V (up to 4) directly with one such relay unit. It is fully powered by the computer USB port. Suitable for home automation applications, hobby projects, industrial automation. The free software allows to control relays manually, create timers (weekly and calendar) and multivibrators, use date and time for alarms or control from command line. We provide software examples in Labview, .NET, Java, Borland C++, Python.

Relay Type:
List Price:$21.35
Discount:$4.50 (21.08%)

Estimated Shipping with Posts

starts at $5.60
Quantity: +-
Send to friendRate this product
Add to wishlist Compare


  • High quality
  • 4 SPDT Relay channels - selectable by user:
    • JQC-3FC/T73 DC5V (7A / 250VAC, 10A / 125VAC, 12A / 120VAC, 10A / 28VDC)
    • RAS-05-15 (10A / 250VAC, 15A / 120VAC, 15A / 24VDC)
  • PCB parameters: FR4 / 1.5mm / two layers / metalized holes / HAL / white stamp / solder mask / еxtra PCB openings for better voltage isolation / doubled high voltage tracks
  • Power supply: from USB port
  • Current consumption: 400 mA
  • Chip: FT245RL. Datasheet - here
  • Power led: Yes
  • Relay leds: Yes
  • Size: 77mm x 56mm x 17mm
  • Supported by DRM software (Windows and Linux): Yes
  • Supported by Denkovi Command line tool (Windows, Linux): Yes
  • Android software available (low cost but very useful): Yes - New
  • Software examples - here
  • Documentation: here



  • High quality
  • Low cost
  • No extra power supply
  • Software with many functions
  • Control electrical devices according weekday/date/time
  • Create timers or pulses with our software



  • Home automation
  • Robotics
  • Alarms
  • Timers
  • Open doors and windows via PC
  • Aquariums applications


Additional information

This is relay board with 4 SPDT Relays controlled from USB port of your computer. The main purpouse of this USB relay module is to help you building projects regarding robotics and home automation (domotic). You may control differenet electrical devices like home lights, DC motors, pneumatic cylinders, lasers and so on. Each such board requires one USB port. The more USB ports you have the more such relay units you may connect and control.

Each such usb relay board is shown as separate virtual com port (VCP) on your PC. The relay module outputs are controlled by FT245RL. It has 8 bit data output register (this device use only 4 of them). When data is sent to the register the outputs are set. If you are software developer - be sure "Synchronous Bit-Bang Mode" is selected! FTDI provides Bit-Bang Mode documentation. See this. The usb relay card can not be controlled directly via COM port - you need to download our DRM Software to control the device. The usb relay unit can not work without PC. Only one such device can be supplyed from single USB port. If you want to supply many such devices you need USB HUB with extra power supply. 


Denkovi Relay Command Line Tool

The main goal of this project is to help you to use our USB relay boards easily and without any specific knowledge how do they work. This tool is actually shell for all our USB relay boards and it does not matter which is the relay board, the command is the same. Just type one command and the the tool will set, get relay status or even will take temperature value from the board sensor (if any). It can be integrated in other software and you don't need to know much about how the USB relay board protocol. With this tool it is like a "game" and it takes literaly minutes to create for example PHP script and control the USB relay board from smartphone browser.

Typical applications for this software are:

  • Create desktop icons to turn particular relays
  • Create BAT/BASH files to make more complex logic (like timers for example)
  • The commands can be executed from PHP script
  • Control our USB relay boards from Android / iPhone mobile devices
  • The USB relays can be controlled from each software/platform which can run external executable files or commands in command line promt

Example commands:

LIST COMMAND - lists all devices connected to computer.

java -jar DenkoviRelayCommandLineTool.jar list 


STATUS COMMAND - display relay(s) status(es).

java -jar DenkoviRelayCommandLineTool.jar DAE0006K 4 2 status

java -jar DenkoviRelayCommandLineTool.jar DAE0006K 4 all status


SET COMMAND - set relay(s) state(s).

java -jar DenkoviRelayCommandLineTool.jar DAE0006K 4 2 1

java -jar DenkoviRelayCommandLineTool.jar DAE0006K 4 all 0

java -jar DenkoviRelayCommandLineTool.jar DAE0006K 4 turn 1110


TIMER COMMAND - exectues time-critical operations. Well known fact is that every time when we run the command line tool the jvm is runned and this takes significant time. Many users contacted us with requests to execute timer commands for time-critical operations. That's why we added such command. It can perform single pulse, many pulses and even cycles with more complex sequences of pulses and every pulse can be with different time (in miliseconds). Please note the state bits must be equal to the relay numer!

java -jar DenkoviRelayCommandLineTool.jar id=1 4 timer 1,1111,10,0000,50,1111,25 //makes all relays ON for 10ms, all OFF for 50ms and all ON for 25ms

java -jar DenkoviRelayCommandLineTool.jar id=1 8 timer 5,11111111,10,00000000,100 //makes all relays ON for 10ms and all OFF for 100ms - 5 times

java -jar DenkoviRelayCommandLineTool.jar id=1 16 timer 5,1000000000000000,10,0000000000000000,1000 //makes first relay ON for 10ms and OFF for 1sec - 5 times


For more information - here

For download - here

Windows: tested on XP, Vista, 7 and 8

Linux: tested on Ubuntu and OpenSuse





Demo video how you can control the USB 4 Channel relay module from command line, browser and tablet the same time because of our command line tool.


DRM Software

The device is supported by DRM Software. DRM Software is Windows/Linux software for controlling all our relay modules. Supported OS:

Windows: tested on XP, Vista, 7 and 8

Linux: tested on Ubuntu and OpenSuse

Denkovi Relay Manager Software (DRM Software) and USB 4 Relay Board
DRM Software image - control mode for USB Four Channel Relay Board


For more information about DRM Software, documentation and download - here

Download the last version (install package) - DRMsetup.exe

Download the last version (intstall archive) - DRMsetup.rar



More videos  

Control USB Four Channel Relay Module from Android Tablet browser
Demo video with DRM Software and USB Four Channel Relay Module




Here it is shown how you can control 5 of these USB Four Relay Modules with one notebook. It is used USB hub expander with extra power supply.



USB 4 Relay Board controlled by Freedomotic home automation framework


DAE USB Relays for Android

This is a low cost but very useful android application developed by iSwicth, LLC. The device is supported by this app and at the moment you can control up to 5 devices at a time with a single phone. Please note that an additional USB hub is necessary.

Android app on Google Play



Useful links:


Software examples

We accept





Scroll To Top