# Programmable relay, 4CH, 5V, USB serial control

> 4-channel 5V relay module controlled via USB (Type-B) using HID interface, driverless, compatible with Windows 7/XP 32/64-bit. Control IC ATMega 8A, relay IC ULN2803, Songle 5V relays, rating 250V 10A AC / 30V 10A DC. COM/NC/NO terminals per channel, status LEDs (green/red). Requires external 5VDC supply to operate relays. Dimensions 72x66mm.

- Page: https://sigmanortec.ro/en/programmable-relay-4ch-5v-usb-serial-control
- Price: 54.39 RON
- Availability: In stock; 1-2 zile
- Reference: 9959 · EAN: 5940043305319
- Category: Electronic components > Relays
- Specifications: Input Voltage: 5 V; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.068 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 04:32 (Europe/Bucharest)

## Description

4-relay 5V module controlled directly from PC via USB, ideal for automation, testing and DIY projects. It is recognized without drivers thanks to the HID interface, compatible with Windows 7 and XP 32 and 64 bits. It offers safe switching of loads via COM NC NO contacts, with status LEDs for each channel. External 5V power supply for actuating the relays and maintaining the state.
4-channel relay module with USB switching, directly compatible with PC. The module is intended for automation applications that require control via the computer's USB interface.
This module uses HID (Human Interface Device) technology, similar to keyboards, which means it does not require drivers to function. It is compatible with Windows 7 and XP operating systems, both 32 and 64 bits.
The module allows easy control of various electrical devices via a PC, thus providing an efficient solution for home automation or DIY projects.
The relays operate at 5VDC, which must be supplied either via the 5.5x2.1mm jack or the adjacent screw connector. The logic part of the module also operates at 5VDC, supplied via the USB type B port.
Each channel has the three common relay ports – COM, NC and NO – which are easily accessible through screw connectors.
As long as the module is connected to 5VDC power, the relays maintain their state even when the computer is disconnected or turned off.
Specifications:
Supply voltage: 5VDC
Channels: 4
Relay voltage: 5VDC
Interface: Integrated USB
Control IC: ATMega 8A
Relay control IC: ULN2803
USB Type: Type-B
Relay type: Songle 5V
Relay rating: 250V, 10A AC and 30V, 10A DC
Control terminal connection mode: NC (Normally closed), COM (Common), NO (Normally open)
LED indicators: Green for relay activated, Red for relay deactivated
Compatibility: Supports Windows 7, XP, 32-bit and 64-bit without the need for additional drivers
USB type: HID (Human Interface Device)
Dimensions mm: 72 x 66mm
Use:
Connect the module to the PC via USB Type B cable (USB cable NOT INCLUDED). Thanks to HID technology, the module will be automatically recognized by the operating system without requiring the installation of drivers.
Connect an external 5VDC power supply to be able to operate the relays and maintain the settings state even when the computer is turned off or the USB is disconnected.
After connecting the module, the software downloaded together with the application data will automatically recognize the current state of the relays.
Use the software to enable or disable the relays according to your needs. LED indicators will show you the status of each relay (red for enabled, off for disabled).
Connect the devices you want to control to the NC/COM/NO terminals of the relays, respecting the specified voltage and current parameters.
Software:
The module works based on the usb_relay_device.dll. There are several approaches to controlling it, some simpler, others more complex.
The module activates the relays ONLY if the 5VDC source is connected!
1. You can try the software provided in this link: EXTERNAL LINK . This is freeware, it lets you operate the relay but to access all the functions you need to purchase it. Software that operates relays based on the COM port does not work because this is a HID device. If you use the software provided above, once downloaded and installed, in the lower right corner you have the automatically recognized channels. The text fields (default marked with OFF) will be filled in with ON or OFF for each channel and, by pressing the Play button, the ON channels will start, the OFF ones will stop. The advantage of this type of software is that you are not limited to simply turning the relays on and off, but you can also create timers and program the relays to act after certain triggers.
2. You can download the software provided in the Download section (you can also find it at this link: EXTERNAL LINK ). It is enough to extract the bin-Win64 folder (or the one according to your PC configuration) and open the GUIapp.exe. Click Find device, if everything is correct you should have the message "Found: 1 device(s)", click Open device and control the relays with Open and Close (active channels are marked in red).