Systems comprising a relaxation oscillator particularly for electrical igniters
AssigneeConstructions Electriques R.V.
InventorBernard Simeau
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Abstract
The invention relates to systems comprising a triggering element such as a thyristor triggered from a relaxation oscillator and relates more particularly to an electrical igniter. In this system means are provided for ensuring the automatic decrease of the intensity of the triggering pulses supplied by the oscillator so that triggering automatically stops after a predetermined time. These means comprise a timing mechanism formed by a resistance inserted in series in the discharge circuit of the oscillator with a capacitor and diode in parallel on the said resistance, the diode being oriented so as to charge the capacitor under the action of pulses supplied by the oscillator. The invention can be applied to an igniter for gas burners.
Claims9
A system of the type comprising a thyristor having a threshold triggering level triggered from a relaxation oscillator, in particular an electrical igniter for gas burners, the improvement wherein said relaxation oscillator comprises a capacitor and a neon tube connected thereto, means for charging the capacitor to the ionization potential of the neon tube, whereby the neon tube conducts and forms a discharge current path for said capacitor, means for providing said discharge current to said thyristor as a triggering pulse, and electronic means for gradually decreasing the intensity of the triggering pulses supplied by the oscillator to an intensity below the threshold triggering level of the thyristor while maintaining the capacitor charging current, whereby triggering automatically stops after a predetermined time while the relaxation oscillator continues to oscillate.
Dependencies are inferred from the claim text.