Newer RLT panels incorporate a timer that allows the user to set an exposure time the RLT panel will remain powered. However, many existing Red Light Therapy panels have been sold without such a timer. This article shows you how to build a timer that will allow you to set an on-time from 1-to-15-minute for your red light therapy panels.

The Timer is placed between the wall power supply and your RLT panel. The Timer is plugged into the wall socket, and the RLT panel is plugged into the Timer.

All parts can be sourced from Amazon.Com. The parts list and URLs are provided at the end of the article. None of the Amazon URLs are affiliate links, so I have no financial gain whether you source these components from Amazon or another outlet.

Step 1: Timer From Amazon

The Timer is rated at 20 amp at 125 volts AC. This Timer is designed initially to go into a home electrical box. Instead of using an electrical box, we use a small rectangle plastic box enclosure.

The timer I choose is a 15-minute timer. This timer is also available in 30 min, 60 min, 2 hours, and more.

Step 2: Drill Front of Enclosure

The Enclosure

Any number of enclosures will work for this project. See the enclosure in the parts list at the end of this article. Mark the center of the enclosure top by drawing a diagonal line from opposing corner to corner, and drill a 3/8” hole where the lines cross. See figure below.

Step 3: Drill Timer Mounting Holes

Next, mount the Timer to the inside of the enclosure top, and mark the two mounting holes for mounting the Timer — Drill 3/16” holes in the marks.

Step 4: Three Foot Extension Cord

Cut the three-foot extension cord in half. Strip and bare the wires on each half of the extension.

The next step is to identify which wire is ground. The ground wire is essential because if you wire the Timer in using the ground wire, the Timer will not be able to cut power to the RLT panels. Therefore, to prevent using the ground wire, we must identify the ground wire. The best way I know how is using a multimeter.

Step 5: Multimeter

Step 6: Find Ground Wire

The multimeter is set to measure resistance (in ohms). By connecting one probe of the multimeter to the plug ground, we can use the other probe to check the wires. The wire that shows no resistance between the plug’s ground and one of the three wires is the ground wire. In this case, the ground wire is colored green.

Step 7: Drill Enclosure for Extension Wire

The next step is to drill two 3/8” diameter holes in the sides, near the bottom of the case. Because the extension is a thick wire, I positioned the holes at a diagonal on opposite sides of the case. Then I passed one end of the extension wire through each hole.

Step 8: Wire the Extension

Once the extension ends are passed through the holes, we connect the two ends of the ground wires from each half of the extension together and twist a wire nut on top to secure the connection.

Step 9: Household Wiring

With the ground wire identified, we can identify the remaining two wires:

Hot — Black Wire. The hot wire is typically colored black. It is the source of the 120 VAC current.

Green Wire — Ground

Neutral — Grey Wire. This wire provides the return path for the current from the hot wire. This wire may also be colored white.

Step 10: Wire the Timer

You can wire the Timer using either the hot wires or the neutral wires to the Timer, and it will function properly.

Step 11: Connecting Wires to Timer

Connect wires to Timer

The Timer has two holes for the wire on the corners of the Timer, line, and load.

First, strip the insulation off the ends of the wire by 3/8”.

Insert the bare wire into the hole, then put the screw terminal in and lock down the wire. See the picture below.

Step 12: Putting It All Together

Mount the Timer to the front of the enclosure using the two screws.

Step 13: Usage

To test the device, plug in a lamp. Turn on the lamp.

Plug the Timer’s plug into a 120 VAC socket.

Unplug the lamp from the socket and plug it into the receptacle on the Timer. The lamp should remain off, until you rotate the Timer know. Rotate the Timer knob for approximately 5 minutes. The light should turn on and remain on until the timer times out. None of the Amazon links are affiliate links. I have no financial interest or gain if you purchase any of these components. Parts List:

Amazon Timer

https://www.amazon.com/gp/product/B000EVS4WG

3-foot extension

https://www.amazon.com/gp/product/B000EVS4WG

Enclosure Plastic Project Box ABS IP65 Electrical Junction box Enclosure Black 6.22 x 3.54 x 2.36 inch (158 x 90 x 60mm)

https://www.amazon.com/gp/product/B000EVS4WG

Digital Multimeter HILTEX 40508 Digital Multimeter

https://www.amazon.com/Neiko-40508-Digital-Multime...