Automatic switching dual power source adapter


DUO AC POWER provides HA ( High Availability ) AC sources, that prevents “SINGLE POINT OF FAILURE” by adding another AC power source available to the single powered computer systems, or other mission critical equipment in unexpected situations of accidentally tripped circuit breaker, or temporarily power grid outages.
The dual AC power features a second power cord (110 VAC or 220 VAC) so that single powered equipment can be connected to two independent branch power feeds. The power cords connect to a power switch (Figure 1) that monitors the AC line voltage on the primary/main power feed (black). By default, all power is drawn from the primary power feed. If the incoming voltage is lost, the power switch automatically draws power from the secondary/backup power feed (white). When power is restored to the main/primary power feed, the switch will continuously validate the AC line voltage for 1 second to ensure the power stability, and then automatically returns the power connection back to the primary power feed.

DUO AC Power has two power inputs: primary and secondary input. Both inputs can accept AC source input @ 110 or 220 volts, 50 to 60 Hz, and 10 Amps maximum. It is recommended that both input power sources have the same voltage set up.

The output should be connected to the equipment whichever needs a HA
power source to keep it operational at all time.

Please be aware that DUO AC Power is designed to replace the existing power cord that connects to computer’s power supply. Not all devices are

Product Overview

DUO AC Power provides an easy and inexpensive method of dual AC power source for mission-critical equipment, ensuring a consistent operation preventing from a possible power loss.


Voltage Indicator

When you plug the power source into the primary or secondary input plug, the Voltage indicator will show orange light for 110V, or green for 220V.

If the input voltage is out of range, the indicator will show red light for abnormal input. Please disconnect the input source in order not to damage DUO AC Power.

Primary source connection

DUO AC Power is designed to channel the primary power source to the output, and use the secondary as a backup source. When you plug in the primary power first, the channel indicator will light up (blue light) to show that the power is now output through the primary source. In the same time, the output indicator will also light up (blue light) to show that the power is sent out through output cord now.

Secondary source connection

After you have connected the primary power source to DUO AC Power, the voltage indicator for secondary input will light up when you plug the power source into the secondary side. The channel indicator will stay on the primary side because the default for DUO AC Power is to send the power to the output from the primary source.

Both sources are connected, but the primary is out

If the primary source is out for any reason, the DUO AC Power will immediately switch to the secondary source without disrupting the equipment operation. The secondary channel indicator will then light up, and the primary source channel indicator will be off.

The primary source is repaired and back online

After the primary source is restored, DUO AC Power will switch back from secondary to the primary after DUO AC Power detects and verifies that the primary power is a continuous and stable source. This test will last for one (1) second to make sure that the primary power can be re-used for the equipment. If the test is completed and DUO AC Power does switch back to the primary source, the indicators will light up accordingly.

Test before connecting DUO AC Power cord online

Once you connect both primary and secondary sources into DUO AC power cord and all the indicators function correctly, there is one more test needs to be performed before connectingthe DUO AC Power to the targeted equipment.

Please follow the “TEST” symbol below the primary voltage indicator, and you can locate a pin hole on the side of DUO AC Power. Push the button once with a sharp object through the pin hole, and then you will find that DUO AC Power is forced to switch to secondary source input after releasing the test button. Since the primary source is connected and functions normally, the DUO AC Power starts the testing and verification process described in section 6.

Once DUO AC Power switches back to the primary source after this test, the system is ready to go. Please connect the desired equipment to the output plug.

Safety and Compliance

This product is not designed for outdoor use. Please only use DUO AC Power at indoor environment.

DUO AC Power has been certified to meet FCC rule based on the standard 47 CFR part 2 and part 15 class B equipment regulations, and cTUVus safety standards.


AC Input and AC Output

Primary Input 100240VAC, 50-60 Hz, 10A

Secondary Input 100240VAC, 50-60 Hz, 10A

Output 100240VAC, 50-60 Hz, 10A

Switching Time

Primary to Secondary <= 14ms,

Secondary to Primary <= 12ms


Blue Active port

Orange 110 VAC


Product size and weight

Size 128*65*32mm (not including cable sets)

packing size 260*90*75mm

Weight 475.75 g


Operating: 0 to 40 C (32 to 122)

Storage: 0 to 70 C (-4to 150)


Operating: 10% to 90% (non-condensing)

User’s Guide