His weight is almost the same like a 28 inches stereo HIFI Television of high class brand of the end of the 80's.
It has VHF CHANNEL Selector and changeable power supply voltages on the rear.
The rear lid is a metallic heavy sheet and seems isolated from the chassis ground which is naturally connected live to mains.
This set was even put on 4 wooden legs with screws on bottom side of the cabinet.
The set has an unique compactness for that era of time were tellyes were normally big as cars.
The B/W Tubes Television set was powered with a External Voltage stabiliser unit (portable metal box) which relates to voltage regulators of the type employed to supply alternating current and a constant voltage to a load circuit from a source in which the line voltage varies.Conventional AC-operated television receivers exhibit several undesirable performance attributes. For example, under low-line voltage conditions such as those encountered during peak load periods or temporary power brown-outs imposed during times of power shortage, picture shrinkage and defocusing are encountered and under extreme brown-out conditions the receiver loses synchronization with a resultant total loss of picture intelligibility.
On the other hand, abnormally high-line voltage conditions are sometimes encountered, and this can lead to excessive high voltage and X-ray generation. In addition, either abnormally high steady state line voltage conditions or high voltage transients such as those encountered during electrical storms or during power line switching operations may subject the active devices and other components of the receiver to over-voltage stresses which can lead to excessive component failure.
It is a principal object of the present invention to provide a new and improved AC-operated television receiver having greatly improved performance characteristics in the presence of fluctuating power supply voltages.
A more specific object of the invention is to provide an AC-operated television receiver affording substantially undegraded performance under even extremely low-line voltage conditions without excessive high voltage and X-ray generation under even extremely high-line voltage conditions.
Still another and extremely important object of the invention is to provide a new and improved AC-operated television receiver having greatly improved reliability against component failure. Such regulators are frequently provided employing saturable core reactors and condensers connected in circuit... in such manner as to provide a plurality of variable voltage vectors which vary in different senses, as the line voltage varies, but which add vectorially in such manner that their vector sum remains substantially constant upon variations in line voltage, for providing automatic voltage stabilization of single or multiphase A. C. circuits where the supply voltage and frequency are subject to variation above and below normal value and where the load is subject to variation between normal limits
The voltage stabilization is automatically effected by the provision of an inductive pilot control device which is adapted to provide two excitation supply voltages for producing excitation or saturation of two magnetic circuits of a reversible booster transformer unit or units and diversion of flux from one magnetic circuit to the other, the booster unit being energized by primary windings from the A. C. supplysystem and being provided with a secondary winding or windings connected between the supply system and the corresponding inain or distribution circuit and in series therewith, through which a corrective boost voltage is
introduced into the circuit under the
The pilot control device which may be employed singly or may comprise three units or their equivalent when applied to multiphase supply systems comprises a pair of closed magnetic circuits or cores constructed of strip wound magnetic material or stacked laminations, the two
circuits forming a pair being constructed of materials possessing dis~similar magnetic characteristics when jointly energized by identical windings in series or by a collective primary winding, the said magnetic circuits being suitably proportioned to provide equal ﬂuxes when energized at normal voltage.
The pilot control device is
the auxiliary secondary winding embraces only one circuit, preferably that subject to the least amount of ﬂux variation. Either of the windings consists of two equal sections or in effect a double winding with a center tapping to which one end of the single winding is connected.
provided with a main and an auxiliary secondary winding or group of windings, the main secondary winding or windings being adapted to provide a voltage representing the difference in the ﬂuxes of the two circuits to which it is jointly associated, while
The voltage in the single secondary winding of the pilot device becomes directionally additive to that in one half of the tapped secondary winding and substractive in respect to that in the other half. When the supply voltage is normal the voltage provided by the single secondary winding is zero, since there is no difference of ﬂux in the two magnetic circuits, and the two excitation voltages
produced in the halves of the other secondary winding are equal and when connected to the two excitation windings of the booster units, do not produce any diversion of flux between the two circuits or sets of circuits in the magnetic system of the booster transformer unit become equal, and since the series winding on the booster unit is arranged to provide a voltage due to the difference of
the ﬂuxes in its two magnetic circuits or sets of magnetic circuits, no corrective voltage is introduced into the main circuit by the booster. If, however, the supply voltage varies from normal the pilot control device provides a voltage across the one secondary winding due to the difference in the ﬂuxes of the two dis-similar magnetic circuits of which it is comprised, which voltage is combined with thosc in the halves of the other secondary winding to provide two excitation voltages which vary complementarily to each other as the supply voltage ﬂuotuates, and cause a transference of ﬂux between the two
circuits or groups of circuits in the booster unit and automatically provide a corrective boost voltage in the main circuit in which the series winding of the booster transformer is includcd of a value equal to that of the variation in supply voltage which initiated it.
The pilot device may be arranged in various ways, forboth single phase and multiphase operation, as exemplified by the constructions hereinafter more fully described.Similarly, numerous arrangements of the booster transformer unit are possible, some of which are hereinafter described in detail. The booster transformer unit embodies thc principles of the inductive devices described in my co-pending Application No. 411,189, ﬁled February 18, 1954.
As an alternative to the provision of an auxiliary secondary winding on the pilot control device this may be
replaced by an independent or external source of supply,which may be either subject to or independent of supply voltage variation, provided such supply may be arranged with a center tapping if required.
Feed-back arrangements may be employed for providing compensation against voltage drop due to the effects of load in various ways. These are preferably providedon the booster transformer unit and may comprise a current transformer in one or more lines of the main circuit,
the secondary output of the transformer being rectified and arranged to energize an additional excitation winding on the booster transformer unit which in clfect increases the amount of the corrective boost voltage as the load increases.
RADIOMARELLI (society of the group Magneti Marelli) has been
one of the most famous radio receivers industries: it was founded in 1891 as
Industria Elettromeccanica Italiana by ERCOLE MARELLI.
And obviously DIED like all Italian Industry..........