US1671109A - Process for increasing the emission in the ultra-violet region from mercury-vapor lamps - Google Patents

Description

May 29, 1928. 1,671,109

I H. GEORGE PROCESS FOR INCREASING THE EMI SION IN THE ULTRA VIOLET REGION FROM MERCURY VAPOR LAMPS Filed May 26, 1925 I n venfof Henri Gear 5 13 his fillTorneyg Patented May 2 9, 1928. v I

UNITED STATES v 1,671,109- PATENT oF-FicE.

HENRI GEORGE, OI PARIS, FRANCE, ASSIGNOB, BY MESN E ASSIGNMENTS, TO HANOVIA GHEKIOAL & MANUFACTURING COMPANY, 01 NEWARK, NEW JERSEY, A CORPORA- TI ON OF-NEW JERSEY.

PROCESS E03 INCREASING 'rnn EMISSION in mm ULTRA-VIOLET moron r301:

unncun'rivaroa Lmrs.

Application filed Kay 26, 1925, Serial N9. 82,959, and in France Kay 80, 1924.

The present invention relates to a process and .apparatus for increasing the emission in the ultra-violet region from mercury vapor lamps.

It is known that mercury vapor lamps with quartz envelopes constitute a source of ultra-violet rays giving an excellent efliciency. It is likewise known that such lamps can be supplied directly with alternating current, by keeping within the conditions defined in the French Patent No. 493,026, dated 24th April, 1918. A comparison of the spectra. emitted in analogous conditions by mercury vapor lamps supplied respectively with continuous current and with alternating current," shows that by varying the voltage and frequency in the latter case the distribution of the energy in the spectrum is varied to a great extent. The applicant has ascertained that the higher the voltage and the frequency of the current supplied, the greater will be the radiation in the ultra-violet region. Thus, for equal amounts of energy expended, a ten-fold increase of certain ultra-violet rays can be obtained when the lam is supplied with alternating current at igh voltage and high frequency.

This method of supply, which forms the subject of the present invention, has thus for efl'ect to increase the efliciency or yield of the mercury vapor lamp as regards ultraviolet radiations.

The invention also comprises an apparatus for carrying out this process; the apparatus is characterized by an arrangement and combination of parts for transforming the alternating currentof the local supply into a high frequency current, connected between the current-supply terminals and the mercury-vapor lamp with quartz wall or envelope.

The accompanying drawing represents d1- a rammatically y way of example a form 0% construction'of this apparatus.

The mercury vapor lamp consists of a tube 1 in the shape of an inverted U made of transparent silica, connecting two vessels 2, 2; the latter contain mercury and are fitted with the electrodes 3, fixed in any suitable manner, as by grinding, sealing, etc. Along the tube 1 there is attachedor fused on a vessel 4, the dimensions of which are calculated so as to ensure stable operation of the lamp. The tube is preferably filled with an inert gas, such as argon or neon,.at a pressure of some centimetres of mercury; the pressure of this gas has for its object to ensure the lighting or starting of the lamp and its operation on alternating current. If

of the local system, and the electrodes 3, 3,

there is interposed the device for transforming the local alternating current into a high frequency current; this device may consist of the conventional arrangement comprising a transformer 6, inductance 7, capacities 8,

8, and spark-gap 9; the mercury vapor lamp is connected, as shown to the terminals of the inductance 7. It is obvious that any other arrangement may be used in which the lamp is connected tothe terminals of the inductance of an oscillating circuit.

Apart from the technical advanta e ofthe increased yield, the process descri e'd presents other advantages of a practical natpre in the'commonest applications of mercury vapor lamps, namely to scientific and therapeutic uses. are comparatively harmless, the process described allows of much readier manipulation of the apparatus without fear of accidents. Another practical advantage results from the fact that the device employed for trans forming the local alternating current into high frequency current may be utilized for other purposes, in the laboratory,: for ex-' ample, for the productionof sparks for spectroscopy, and b medical practitioners, for example, for big i-frequency treatment, es ecially diathermy; this allows of considera le saving in the total cost of equipment.

What I claim is:

1-. In combination with a mercury vapor lamp having a quartz envelope, means for increasing. the ultra-violet emission of the lamp comprising a source of high frequency, high voltage current, and means for connecting the terminals of the lamp to the termi- 86 Since high frequency currents I nals of saidsource of current so that'the mercury vapor in the lamp will serve as a conductor of the high frequency, high voltage current.

'2. In combination with a mercury vapor lamp having a uartz envelope, means for increasing the u tra-violet emission of the lamp comprising a source of current, means interposed between the lamp and the source of current for converting the supply'current' into high frequency high voltage'cur'rent, the terminals of the lamp being so connected to the interposed means that the mercury vapor in thelamp will serve as a conductor for the high frequency high voltage current.

3.- An apparatus for increasing ultra viowith quartz envelope comprislng a source of current, a high frequenc high voltage oscillating circuit interpose between the lamp and the source of current, said circuit comprising the secondary of a transformer in parallel with an inductance, a spark gap, and condensers in series with the inductance, the terminals of the inductance being connected to the terminals of the mercury vapor lamp so that the mercury vapor in the lamp Will serve as a conductor of the high frequency high voltage current.

In testimony whereof I have signed my name to this specification. I HENRI GEORGE.

. let ray emission of a mercury vapor lamp

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