Helium Neon Laser Power Supply
Posted on Jun 9, 2012 9725
Under: Laser Circuits
The first 5 circuits described in the following sections were reverse engineered from commercial HeNe power supplies. There may be errors in transcription as well as interpretation. In many cases, the transformer secondary voltage was not marked and where the actual hardware was not available for testing, an estimate of its value was made. Many of these designs are quite old since modern commercial units tend toward inverter designs since they can be more compact and have higher efficiency. Unfortunately, these are nearly always potted in Epoxy and impossible to analyze.
The last one I built using the scrounged power transformer from a long dead and cannibalized tube type TV and a pair of high voltage capacitors (for the main filter on the doubler) that had been sitting in a box minding their own business for the last 15 years. My total cost for the remaining components was about $5. AC Line operated power supplies will drive HeNe tubes just as well as fancy inverters and are somewhat easier to construct and troubleshoot. The line side circuitry is not shown for any of these. See the section: "AC input circuitry for HeNe power supplies" for details. Edmund Scientific HeNe power supply: ----------------------------------- There were some inconsistencies in the component values of this circuit when I first saw it. I have adjusted the RMS value of the transformer down from 710 to 650 VRMS so that the numbers work out closer to what one would expect. Estimated specifications (Edmund Scientific): * Operating voltage: 1,700 V. * Operating current: 4 mA. * Starting voltage: around 5,300 V. * Compliance range: NA - no regulation. (Portions from: Steve Nosko (email@example.com)). The 650 V transformer output feeds a voltage doubler (D1 to D6 and C1 to C4) resulting in about 1,750 V across all the electrolytics. (Slightly less than 2 times the peak value of 650 VRMS.) D7 to D12 and C5 to C7 form a classical voltage multiplier ladder which generates a peak...