I’m sharing this information because when I searched the internet for details on the Delta range of products, I found nothing. Hopefully, this will help anyone who owns one of these units.

What is the Delta 33 Mains Switcher?

The Delta 33 Mains Switcher allows you to control three IEC mains outputs with a maximum load of 3 Amps. You can switch the device on using either a simple contact closure or a low voltage trigger, making it versatile for a range of uses.

How to Operate the Delta 33

• Using a Low Voltage Trigger (up to 12v DC):

  • Pin 1: Positive
  • Pin 2: Negative
  • At 12v, the internal relay seems to draw approximately 10mA.

• Using a Contact Closure:

  • Short Pin 2 to Pin 3.

A Bit of Background

I haven’t been able to dig up much about the company behind these devices. The circuit board has "3dB Ltd" etched on it, but when I looked up 3dB Ltd, it seems to be a 3D graphic design company now, so it must pre-date their current focus.

Recognising the Delta 33

The units are easy to spot thanks to their bright green cases. Along with the mains switcher, I also own one of their audio distribution amplifiers, which follows a similar design.