GB573177A - An automatic control system for electrical vibrating apparatus - Google Patents

Abstract

573,177. Automatic control systems for electrically vibrated mechanisms. TRAYLOR VIBRATOR CO. March 22, 1943, No. 4669. Convention date, March 28, 1942. [Class 38 (iv)] Weight.-A system adapted to maintain constant the loading of a conveyer, actuated by vibrating apparatus, comprises a magnetic member 33 movable in relation to a magnetic core 30 in accordance with the loading and adapted to control the current supplied to the coils 15 operating the vibrating apparatus. Coils 31, 32 fed with alternating current generate voltages in coils 35, 36 which are normally equal, but vary in opposite senses as the member 33 moves from its mean position. These voltages are applied to the input circuits of amplifiers 23, in pushpull, which, through similar amplifiers 24, produce on the primary winding of a transformer 43 a voltage which is normally nil, but is of reversible phase and variable amount in accordance with the position of the said. member. The coils 15 of a vibratory motor or other control therefor, such as a saturable reactance or transformer, are supplied through a rectifier 13 having a control grid to which is fed an A.C. voltage normally lagging 90 degrees on the anode voltage, and condensers 58 in series in the grid circuit are adapted to introduce a D.C. voltage varying with the position of the member 33 to shift the phase of the ignition instant in each cycle of anode voltage of the rectifier 13 so that the loading of the conveyer may remain constant. A transformer 48 supplies current through rectifiers 25, 26 in opposing senses to resistances 51, 52 so that normally the voltage across their series connection is nil and the transformer 43 superposes on them through the same rectifier, its aforesaid variable voltage. An adjustable resistance network 60 having a tapping 59 is connected in series with the resistances 51, 52 in a shunt circuit charging and discharging the condenser. The effect may be to apply to the grid an instantaneous increment of voltage when the member 33 changes its position or a gradual change in that voltage according as the tapping is to left or right of the network 60 ; both effects are combined in intermediate positions of the tapping. Specification 487,099 . is referred to.