Instructions for Wiring the Copper-Covered HeNe Laser Power Supply

This is detailed info on assembling the copper-covered HeNe laser power supply bricks with ballast resistor that have been provided with the stabilized laser kits. There are two types of HeNe laser tubes which differ in which end produces the output beam and which end produces the "waste" beam which may be used for the stabilization feedback. The diagrams below show the general arrangement for both. Note that the wiring must be identical:

Copper-Covered HeNe Laser Power Supply Brick Wiring Diagrams

Wiring the power supply

Attach the thin red and yellow wires (tied together) to the positive of the wall adapter. Attach the short black wire to the negative of the wall adapter. DOUBLE CHECK THE WIRING. REVERSE POLARITY WILL BLOW THE HENE LASER POWER SUPPLY OR DAMAGE IT SUCH THAT THERE IS NO OUTPUT CURRENT REGULATION - WHICH WILL DAMAGE THE TUBE. AND MAY BLOW THE WALL ADAPTER AS WELL.

CAUTION: ALL INPUT WIRING MUST BE SECURED USING SOLDER, WIRE NUTS, OR A SUITABLE CONNECTOR. DO NOT JUST WRAP THE WIRES TOGETHER. INTERMITTENT CONNECTIONS BLOW STUFF.

(These are not provided with detachable plugs and jacks for the DC power because of the risk of accidentally swapping them for the heater supply, which would blow the HeNe laser power supply brick.)

Installing the tube

  1. Examine the mirrors of the laser tube to determine the end for the main beam. In the past, most of these were from the anode-end but it can come from either end depending on the specific tube. There will be an AR coating on the output-end mirror which appears blue-ish in reflected light.

  2. Solder a short piece of high voltage wire to the 91K ohm ballast resistor and solder a tube clip to the wire. This wire should not be more than 1-2 inches in length.

  3. Solder an extension to the remaining thin black wire so it will reach the cathode-end of the tube and solder a tube clip to it.

  4. GENTLY press the tube clips onto their respective ends of the tube. DOUBLE CHECK THAT THEY GO TO THE CORRECT ENDS: THE ONE WITH FAT RED WIRE AND BALLAST RESISTOR MUST GO TO THE ANODE (GLASS) END OF THE TUBE!

With everything connected, power the wall adapter. The tube should light within a couple seconds. If it does not, go back and double check everything!

WARNING: THE VOLTAGE BETWEEN THE ANODE AND CATHODE OF THE LASER TUBE MAY BE GREATER THAN 5,000 V WHILE STARTING AND GREATER THAN 1,000 V WHEN RUNNING. TOUCHING THIS WILL PROBABLY NOT BE LETHAL BUT YOU WILL FEEL IT AND PERHAPS TOSS THE ENTIRE RIG ACROSS THE ROOM. :( SIGNIFICANT CHARGE WILL REMAIN ACROSS THE TUBE AND POWER SUPPLY FOR SOME TIME AFTER INPUT POWER IS REMOVED. DISCHARGE ACROSS THE TUBE BEFORE TOUCHING ANYTHING TO BE SAFE.