GB1095029A - No break generating set - Google Patents

Abstract

1,095,029. Transistor pulse circuits; transistor amplifiers. A.G. FUR INDUSTRIELLE ELEKTRONIK. Nov. 11, 1965 [Sept. 6, 1965], No. 47998/65. Addition to 1,057,448. Heading H3T. [Also in Divisions G3 and H2] In a " no break" A.C. supply system as disclosed in the parent application comprising a battery and mains fed charging unit feeding a thyristor inverter, two inverters 5, 6 are utilized having their inputs in parallel and phase displaced outputs in series, the extent of the phase displacement being controlled by a differential amplifier 8 responsive to a combined output so as to maintain the output voltage constant. The inverters are normally fed directly from a stabilized rectifier unit 1, but on failure of the supply from a trickle charged battery 2 through a diode 4. The frequency is determined by a quartz crystal 900 (on Fig. 2B) followed by a series of frequency dividing stages 901 to give outputs at A and B of 50 c.p.s. displaced by 180 degrees which are amplified by transistors T1-T4 and passed through differentiating circuits 32, 35 and diodes 36, 37 to give a series of positive pulses to a monostable circuit T5-T7 which has a square wave output L of variable width dependent on the signal H from amplifier 8, which signal has a threshold value determined by a Zener diode 39. The signal L is passed through a transistor T8, a Schmitt trigger circuit T9, T10, differentiating circuits 57, 58 and 65, 67 and diodes 59, 66 to a flip-flop circuit 11, 12, the diode inputs being synchronized through resistors 30, 31 with the outputs of transistors T2, T4. The flip-flop output 0 and a high frequency input P from a multivibrator circuit (Fig. 2C) including transistors T17-T20 is fed to a AND circuit formed by diodes 68, 69 to give a resultant signal Q which is supplied to transformers 82, 83 after amplification by transistors T13-T16. These transformers fire one pair of thyristors, e.g. 119, 126 and similar circuits (Fig. 2C) supply other pairs. The thyristors pass the battery current to transformers 143, 144 whose series connected secondary windings give a stepped square wave output to a load 149 whose voltage after rectification is sensed by the differential amplifier 8 comprising transistors T21, T22, which compares the voltages across potentiometers 157 and 164, 165 the output being amplified by transistors T23, T24 and passed to transistor T5. A resistor 170 provides negative feedback and improves linearity. Commutating circuits are provided for the thyristors as shown. The arrangement may be multipled to give a polyphase output.