Radio Electric Pvt Ltd Girgaon, Mumbai, Maharashtra

This is a very compact Motorized Variauto which uses the coil cavity to fit the motor assembly. We use roller brushes in this product for low torque and smooth operation. The speed of the motor can also be varied (time span for one rotation) by varying the DC voltage. * Built in DC motor* Models from 2Amp to 15 Amp in both single layer & double layer* Very compact, with no assembly* Ideal for EXPORT as it drastically reduces size and weight of equipments like HV Tester, SCVS, Power supplies, etc.    

  This is a new concept & can be used in powerfactor correction panels for adjusting the Inductance value. This harmonic Filter choke is manufactured using Cu strip wound edgewise thus making its size compact. These chokes can also be manufactured in single phase using toroidal core with air gap. This can be also used in Engineering College, Laboratories on the Test bench for adjusting the Parameters in the electrical circuit.

Driven Type : Electric

Power : 1-5kw

Windmill / Solar & Energy Saver ApplicationThese transformers are silent in operation, compact in size, less weight and are ideally suitable 24/7/365 operation due to very low no load losses. Isolated (OW) type• Capacity 50VA to 12 KVA• Three Phase Assembly• High Efficiency Energy Saver Transformers Auto Type• Capacity upto 30 KVA• Three Phase Assembly• Efficiency of 99% is possible in Energy Saver Application     Torroidal Transformers are gaining more and more acceptance due to its unique features and advantages. In fact, because of its low weight & height it is being increasingly preferred over theconventional E&I transformers. In certain applications, its low magnetic stray field & the low mechanical hum are the most advantageous features. The low no load losses of the Torroidal Transformer are of great value in 24 hours stand by equipment. This transformer being custom built proves very economical in large production batches. Dual out-put voltages can be provided if desired. It is also possible to have primary suitable for 115Vor 230V AC, 50Hz.  A Thermal cut off can be incorporated as a special feature at an extra cost. Our manufacturing experience of number of years has given us extensive knowledge & insight in designing the Torrodial Transformer. We use high quality material inputs in order to maintain the quality. The INSULATION between the primary & secondary winding is a fundamental safety feature,and to ensure this we use only,BIS (Bureau of Indian Standards) approved insulating material. Special attention is given to insulation resistance, Hi-pot test & creepage distances.

These models are generally used in laboratories, educational institutions, test benches for testing various industrial equipment. They can be provided with MCB, indicators and switch gear as required. All three phase open construction models from 2 Amp to 60 Amp can be enclosed and freely movable trolley can be provided. Output voltages can be tailor-made as required.

The Roller brushes used in these variautos are manufactured from special graphite slabs & have a metal insert. The movement of the carbon brush on the variauto track is with minimum friction, thus it is very very smooth & effortless. It also ensure longer life. Models available are 2A, 4A, 8 Amp. 10Amp. We can also give higher rated models of 15 Amp, 20 Amp, 28 Amp for oil-cooled applications.

The Variautos offered by Radio Electric is a simple & rugged method to control power, voltage & current. They are designed for heavy duty continuous use. They can provide high current rating, & overload capacity. Radio Electric specilises in design tailor made variautos.They are commonly known as Variac Auto Transformer. This is a motorized version of Single Layer Variauto. We manufacture it using top quality motors, Micro Switches and rugged construction. The side studs and center shaft are well insulated from each other to avoid completion of magnetic circuit. Models available are 2 Amp, 4 Amp, 6 Amp, ….upto 35 Amp. For Models above 40 Amp, we use side wiping contacts. The commutatorsurface on these coils are machine processed and hence are very even and smooth. This ensures very less torque for the motor enhancing its life.

This Variauto construction looks like a conventional 3 ph transformer as can be seen in the picture. The spatiality of this lies in winding Cu strip of appropriate cross section edgewise. This reduces the length of the column to 1/4 as compared to winding widthwise thus making it compact. This column is then polished & roller carbons are made to make contact with winding for current collection. Due to circular column construction, a Double Carbon assembly can be provided giving two outputs 1800 out of phase (or as it is known + and - type). Then this type of variauto can give +/- type output with carbon assembly moving in opposite directions (up/down). For large current ratings these columns can be paralleled. Also being in three phase construction it can be used for higher Currents in delta (p) type connections.This finds application mainly in Plating rectifiers, high voltage Testing Equipments, high power automatic voltage regulation (Servo Stabilisers)

We specialize in the manufacture of high current rated coils. The commutator surface of our coils is machine processed and hence very uniform and smooth. This is very important for proper collection of current by the carbon brushes thus reducing the heat generated. Our standard coils are 100 Amp, 150 Amp, 200 Amp. Using these coils we manufacture oil-cooled variautos from 100 Amp 3 Ph to 1200 Amp 3 Ph capacity (415 V input and 0-470 V variable output). In high current rated models we use multiple coils with properly rated balancing coils to achieve the rated current. Based on the calculations of cooling area appropriate no. of radiators &fins  are used. These variautos are generally motorized with geared mechanism. We also cater to tailor-made requirements.

We specialize in manufacturing High Current Air Cooled Variauto in Single Phase & Three Phase 100A, 200A, 400A. The picture shows single phase Variautos 200A each. Three Phase units are built by using such three stacks & motorizing them on common shaft. This is a substitute for Oil cooled units which are less preferred in many non hazardous application for safety reasons. They are very easy to maintain & service. Enclosed units can be manufacture as shown ( 200A, 440V ). These variautos are more preferred for safety reasons over Oil Cooled variautos.

  Engineers, Scientists, Technicians working in laboratories on sensitive equipments have a need for Isolated mains supply, with a variable output Voltage. This facilitates them in testing various devices demanding different voltages & currents. It is also an Electrical Engg. practice to test devices by applying steadily increasing voltage from 0 V to the device rated voltage. To achieve the above objective, it is normal practice to use a Variauto followed by a 1: 1 Isolation transformer or vice versa as shown in figure 1. This combination becomes very bulky (heavy) with two separate transformers, wiring or a combined bulky box. occupying much of test test bench space. This is more so as the current rating or VA increasing. It looses its mobility. Radio Electric has solved this problem by designing a "Double Wound Isolated Variable Transformer". This elegant & compact arrangement uses only ONE Transformer on a Single torroidal Core. This provides 2.5 kv Isolation between prim & sec, prim & body with a Variable Output Voltage from 0V to the required voltage. Various models are as Illustrated in table 1.This concept can also be used very effectively in DC power supplies with Variable output (eg. Input 230V / 110 V, Output 0 to 25 V, 5A or 0 to 15V, 8 Amp. etc.). We also manufacture in table-top models with various types of input/output sockets (Shuko / Dual type / Round type, etc.) as required.       MODELS   Radiotone  DW  Isolated  Variable Transformer I/P 125 V, 60 Hz supply voltage & output Variable from 0 to 150 V

The DL (Double Layer) Variauto was specially designed in 1982, for the Servo Controlled Voltage Stabiliser Industry. Since then we have supplied thousands of such Variautos to the Industry & we can claim to be pioneers in India in this field of Variautos.This DL Variauto combines the functions of Variauto and Buck Boost Transformer for the required range of Voltage. It makes the whole unit very compact, thus reducing the size of Servo Stabilizer Cabinet. The DL Variauto increases the productivity on Shop floor as the assembly & writing are considerably reduced. Its Electrical connection Diagram is already in the Main Brochure. We can tailormake this Variauto to suit your specific voltage range (i.e. 180V - 260V or 85 V - 135 V as required).

This is also a three phase transformer, however with each limb having one winding inside. The top winding is connected in series with inside winding. The Carbon brushes are on the outer load winding. This VARIAUTO has special application in Servo controlled Voltage Stabiliser with balanced loads & balanced input conditions. It can be also used for unbalanced load conditions upto a certain extent. This eliminates the 3 phase buck boost transformer thus making the TANK SIZE very compact. Presently ready model is suitable for 45 KV A, 3 PhStabiliser. Further models are under development.

  These are tailor-made products used mainly for Testing High Voltage High Power  Motors & Switch gears. We have manufactured and supplied such units to UL India. 0 to 660V, 3Ph, 100A with pre-settable voltage