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 While they have been with us for many years, fluorescent lamps remain somewhat mysterious to most people. This isn't really surprising, since their operation isn't simple. The tube itself contains a mixture of gases, but the active ingredient is mercury. When operated as an arc, mercury vapour emits a vast amount of short-wave ultraviolet light. This is invisible, but phosphors on the inside of the tube itself fluoresce when struck by UV, and are designed to emit visible light. Most of the remaining UV light is absorbed by the glass, which is opaque to ultraviolet (this is why you can't get a suntan from behind a glass window). Refer to Figure 1 to follow the explanation . This also shows a representation of the fitting that was used for the illumination tests. For all tests, only the centre tube was installed, with the others removed to ensure that each lamp was operating under near identical conditions . Figure 1 - Wiring Diagram For a Conventional "Troffer" ...

Nixie tubes are cool. They have great aesthetic appeal with their difficult-to-photograph, warm orange glow, and dem curvy numerals. They add an organic je ne sais quoi to a hobby with ostensibly digital design cues. Further, they pose technical challenges in the way of producing and switching the ~175 V DC needed to light each tube element.  And as far as I am aware, there are no new nixie tubes being produced; as such, procurement can be a challenge unto itself. My N.O.S. nixies came from Russia thru Ebay, and only 3 were duds. Incidentally the seller replaced those 3, FOC. [ ]

Tube Power Amplifier 35W Push Pull is made using a tube and eventually compiled configuration push-pull amplifier. Tube Power Amplifier 35W Push Pull tube til it using EL-34 as the amplifier end. In the power amplifier that is made with a tube at a glance looks simple because the use of active components that are not complex. It should be noted that the use of tubes in Tube Power Amplifier 35W Push Pull require a high voltage supply, therefore in the process of making and finishing must be careful of high voltage and radiation. Detailed series of Tube Power Amplifier 35W Push Pull can be seen in the following figure. Tube Power Amplifier Series 35W Push Pull Sign Components Tube Power Amplifier 35W Push Pull R1 = 470K 0.5 W R2-5 = 2K2 0.5W R3 = 150K 0.5W R4 = 220K 0.5W R6-10 = 56K 0.5W R7 = 3.9K 0.5W R8 = 220R 0.5W R9 = 1M 0.5W R11 = 39K 1W R12-23 = 180K 0.5W R13-21 = 820K 0.5W R14-22 = 5K6 0.5W R15-20 = 680K 0.5W R16-19 = 100K 0.5W R17-18 = 3K3 1W R24 = 470R 2W TR1-2 = 470R 1W Variabl...

Flashing neon globes have use in many applications, however their relatively high working voltage precludes their general use where a mains supply is not available . This simple neon tube flasher circuit enables neon tubes or bulbs to be operated from a low voltage dc supply. The voltage required to ignite the neon tube is obtained by using an ordinary filament transformer (240-6.3Vl in reverse . Battery drain is quite low  being in the region of 1 to 2 milliamps for a nine volt battery. O1 is a unijunction transistor and operates as a relaxation oscillator. its frequency of operation is determined by R2-C1.  The pulses from Q1 are directed to O2 which in tum drives O3 into saturation. The sharp rise in current through the 6.3V winding of the transformer as 03 goes into saturation induces a high voltage in the secondary winding causing the neon to flash.  The diode D1 protects the transistor from high voltage spikes generated when switching currents in the transformer...