Instant start solid state ballast for fluorescent and gas-dis charge lamps

Abstract

 The standart Ballasts and starters used for the fluorescent lamps are based on the voltage kicks of a dying magnetic field in iron core. This is a somewhat artificial way of obtaining the voltage gradient necessary to establish an arc in the long vacuum tube. To facilitate this arc a cathode heating has been added for electron emission and arc starting.
In the new design:

1- Instead of a weak voltage increase a dependable high voltage level is created by the sound autotransformer principle.

2- instead of having the fully rated voltage primary coil, a much shorter one is subjected to the rated voltage for a few seconds and also protected from damage by a carefully chosen PTC (Posⁱtif Temperature Coefficient Thermistor) to separate the primary from the rated voltage circuit.

3- Therefore, with the aid of the PTC, from a 1 : 2 ratio autotransforme a voltage of 3 x V (rated) is obtained instantly.

4- This very short durated voltage is enough to strike an arc even for a very low (140 V) network and light a lamp without a starter.

5- This high voltage is harmless since it has the secondary coil in series as a ballast in the lamp circuit.

Description

[0001] The standart Ballasts and starters used for the fluorescent lamps are based on the voltage kicks of a dying magnetic field in iron core. This is a somewhat artificial way of obtaining the voltage gradient necessary to establish an arc in the long vacuum tube. To facilitate this arc a cathode heating has been added for electron emission and arc starting.

In the new design:

[0002] 

1- Instead of a weak voltage increase a dependable high voltage level is created by the sound autotransformer principle.

2- Instead of having the fully rated voltage primary coil, a much shorter one is subjected to the rated voltage for a few seconds and also protected from damage by a carefully chosen PTC (Positif Temperature Coefficient Thermistor) to separate the primary from·the rated voltage circuit.

3- Therefore, with the aid of the PTC, from a 1 : 2 ratio autotransforme a voltage of 3 x V (rated) is obtained instantly.

4- This very short durated voltage is enough to strike an arc even for a very low (140 V) network and light a lamp without a starter.

5- This high voltage is harmless since it has the secondary coil in series as a ballast in the lamp circuit.

Thus the advantages are:

[0003] 

1- Very small amount of iron and copper is used.

2- High power factor.

3- Instant start.

4- No need of a starter and preheated cathodes.

5- Longer life for the lamps even the use without a cathode.

6- Simultaneous operation of any number of lamps connected in parallel.

7- From 130 - 250 V voltage change no appreciable in light output.

8- The saving in power use is 500% around 150 V and 200% around 220 V compared to the old system.

Claims

1- The use of PTC (2) on the primary to permit very short windings (4).

2- Use of auto-transformer principle to obtain high voltages easily (4), (5).

3- This high voltage and the use of a small capacitor (3) permit the simultaneous parallel operation of several lamps (7).

4- A safe high voltage during operation for the independent control of lamps lighting due to the open primary (2).

Drawing