As they say, “Necessity is the mother of invention”  this product came from a need to power up six 200W power supplies on a machine without over loading the mains supply on start-up. Switching on the power supplies one at a time overcame the problem.

SEQ8 Relay cards for large power supply start up sequencing

On power up, the 8 Opto-isolated relays are sequentially enabled by a dedicated processor at 1-second intervals. The relays remain energised until the power is removed. The individual digital signals are available, along with power on a 15-way, D-type connector.

Changeover Relay (SPDT) outputs are accessed via two-part connectors in the example shown. This version uses 6V rated relays for low power consumption at 5V operation.

Sequential start up could be useful for applications requiring timing & sequence. We can customise SEQ8 settings. 

The SEQ8 range of cards, with 5V or 6V, & single or two part connection options is the latest to join Easydaq’s vast range of relay card & data collection cards. All Easydaq products are designed & built in the UK.

Relay card uses, variations & configurations

Relay cards are incredibly useful in providing control over systems. Typical applications include security & access, control of laboratory & medical equipment, pump & irrigation control, test equipment operation, military applications, & monitoring equipment control. Not limited to industrial use, relay cards are an integral part of scientific, academic, & research projects as well as home automation & hobbyist applications. 

Easydaq cards vary from 4-96 relays & they are code compatible. There are signal or power relays. Power versions are available with 5V,6V or 12V operating relays. The boards can be digital, serial, USB & Ethernet controlled.

Let’s have a look at the USB4SRMx…

This one is USB controlled & powered, with 4 opto-isolated relays & four general purpose digital I/O channels. 

The relays are high sensitivity (gold contact) signal relays (30V DC at 1A). Access to all relay contacts & the 4 DIO channels is via fixed screw terminal block connectors along the edge of the card. 

It is suitable for a wide range of control & signal switching purposes. There is screw terminal access to the USB power for possible onward powering/use in your target system. There are +5V & relay channel LED status indicators. 

Nylon feet are fitted in each corner, which will take self-tapping screws. They can be removed to allow the cards to be mounted on pillars or stacked.  A Perspex cover can add general protection of the card & prevent accidental contact with relay contacts or screw terminal connections.  DIN rail mounts will fit.

Plug it in & it will be recognised as a serial port. Once setup, you can access or control from any web/browser enabled device or phone. Program using C++, LabVIEW, Java, Perl, Python, Ruby, PHP or Ajax options.


Relay cards can be stacked.






or Mounted on a DIN rail







Or they can sit on their own four feet!






The Future

As code for the various processors used in the range of relay cards can easily be written, a whole new branch of possibilities opens up. Easydaq can provide customised programming & welcome ideas for new products, variations & applications.

Easydaq is based in Wareham, Dorset & was established in 2002. It is owned by Greenhalse Electronics.

Telephone 01202 916411

Easydaq, & Greenhalse Electronics, 1 Designer House, Anglebury Business Park, S&ford Lane Industrial Estate, Wareham, Dorset. BH20 4DY.

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