SU665414A1 - Power supply source for treatment of articles with aid of glow discharge - Google Patents

Description

glitter discharges and the cathode of this chamber. The positive terminal is connected to the housing of the discharge chamber 22, which is the anode of this chamber. Capacitor 3 is included in the diagonal of the thyristor bridges formed by thyristors 4-7, 8-I, 12-15 and connected between the same phases aa, b-b, and c of the secondary windings groups 16, 17, respectively.

The operation of the power source is as follows.

FIG. 2a, b, c, the current time is plotted on the abscissa axis, and the ordinate axis in FIG. 2, a - values of the phase voltages and secondary windings of the power transformer; in FIG. 2, b - values of the voltage f / 2 on the capacitor 3; in fig. 2, e are the instantaneous voltage values 1/3 of the average voltage U on the discharge chamber 22.

Suppose, at the time moment (Fig. 2), control pulses are applied to thyristors 4, 8, 12, 7, 11, 15, and the capacitor 3 is by this moment charged up to the supply voltage with the polarity indicated in FIG. 1. This includes the thyristor 4, since the greatest positive voltage is applied to its anode, and the thyristor 11, due to the fact that the greatest negative voltage is applied to its cathode (Fig. 2, a). The capacitor 3 is recharged (Fig. 2.6) through the load (discharge chamber). In this case, a voltage pulse t / z (Fig. 2.0) is formed on the load, the shape of which depends on the parameters of the converter and the load, and the energy in the pulse is constant and equal for the case of the active load

W ICUab,

where W is the power supply pulse energy;

C - capacitor capacitance 3; Uab - power supply. At the next time point, after the polarity of the voltage on the capacitor is reversed, control pulses are applied to the thyristors 6, 10, 14, 5, 9, 13, the thyristors 6, 9 are turned on, and the capacitor is recharged again through the load. Then at the time point, the control pulses are again fed to the thyristors 4, 8, 12, 7, 11, 15 and the processes in the circuit are repeated.

In this scheme, the converter is easily protected against short circuits of the load by removing control pulses. In this case, for any change in the parameters of the load and, in particular, in the event of a short circuit of the load, the energy transferred to the load is strictly limited. This eliminates damage to the products when they are treated in a glow discharge at

the transition of the latter to the arc discharge due to the strict limitation of the energy supplied to the products during each arcing. By changing the frequency of recharging capacitor 3, one can regulate the average value of the voltage I / (Fig. 2, b) or the power in the load with a high transducer relative to the network, since the control angles of the converter's shoulders during regulation are zero. In addition, if one introduces the phase control of the converter's shoulders, as is customary in the known slave converters, it is possible to make amplitude control

voltage on the load, without excluding the frequency control.

Claims (2)

1. Patent of Great Britain No. 1255321, cl. From 7V 9V1, published. 1972. 2. USSR author's certificate number 548930, cl. H 02M 7/155, 1976. , 3 22, 20 to t ,, t.