For sale is antique radio power transformer. Features:

- High Voltage: 275-0-275 40MA - Secondary Power Supply: 3.15-0-3.15 1.9A - Voltage: 0-4-5-6.3 1.5A - Number of Valves: 4 - Primary: 230V - Power: 43VA - Measurements: Length 7.5 cm x High 6.3 cm x Width 7 cm - Weight: 1.3 Kg - Measurements between holes: horizontal position: 6.2 x 5.7 cm, vertical position Made in Spain, high quality copper. The price is per unit. We have more transformers of different capacities. For more information, see the photograph. Ref. 1-17051 POWER TRANSFORMER FOR RADIO DEVICES, AMPLIFIERS, INSTRUMENTS, SOURCES, ETC. DESIGNED WITH VALVES The fixing system consists of two equal frames that evenly press the core avoiding any type of noise produced by vibrations. In the horizontal position, you get a wide base and a point of low gravity that allows mounts in places of limited height Upright is frequently used on antique radios, primarily in all PHILIPS brand ranges and the like. Slots in frames allow you to attach some components, valve sockets, voltage changes, etc. that some manufacturers used to mount.  By disassembling the corresponding frame on the side of the connections, the transformer can be mounted in the trans-chassis position, also prevalent in many radio mounts and amplifiers, especially those from mounting kits. This type of assembly requires a longer length of the screws that are supplied. Once mounted, the frame can be dispensed with for better access to connections, or retained for greater consistency in fastening.  POWER TRANSFORMERS FOR THERMIONIC VALVE APPLIANCES.  The power transformer is responsible for converting the power grid voltage applied to the transformer primary, into the different voltages required in the secondary circuits.  For this reason according to current regulations, insulation between the two of 4000v must be guaranteed. The input socket should be protected by a fuse that supports the total power consumed by the computer.  E.g.  The 17031 model has a power of 65va. Applying Ohm's law yields a current at full charge of: 65va /230v = 0.28A.  Increasing this margin by 12%, the fuse in question for a normalized current value will be 315mA-L (slow fusion) The voltages supplied by the transformer are expressed in alternating current, AC (Alternating Current) and must be converted to direct current, DC (Direct Current) to power the various sections of the receiver equipment or amplifier. This function is handled by the rectifier circuit and may incorporate a valve or semiconductor diodes.  The transformers featured here incorporate separate winding for grinding valve filament heating with 4, 5, and 6.3V outlets.  These voltages cover most existing grinding valves. The AZ41 is heated with 4v, the GZ34 with 5v, and the EZ81 with 6.3v as an example of three very common grinding valves in radios and amplifiers.  The winding described for heating the rectifier valve under no circumstances should be used to power other elements, as this  is connected to high voltage, DC.  High voltage secondary is performed with two windings symmetrically joined by a center socket.  The voltage and current value come determined by the number of valves to be powered.  Extreme safety precautions are recommended to protect yourself from potential discharges. The tension between ends of this winding is, in  the largest of the models, over 750v...  Secondary to other filaments and dial lamps is 6.3v with center socket and labeled 3.15-0-3.15.  The center socket is grounded to prevent noise. (50 Hz buzzes.)  Only in the event that it is not grinded with a valve, the winding intended for the 6.3v grinder can be used for other purposes, it can be connected in series or in parallel with other filament windings, adding up the intensities or stresses of both.  For example on the 17032 model we can get a 6.3v and 5A winding connected in parallel or a 12.6v 2A winding if connected in series.  To choose the transformer model that best suits our needs, the easiest method for a given repair is the size of the transformer, as this usually determines the total power required by the appliance. Having the measurements of the original we will only have to choose from the three offered the closest.  In the specifications of each valve, we will have the voltage and intensity values of the filaments and adding that of all the valves that the appliance has, we can choose from those offered.  Typically the 40va model will serve 3- or 4-lamp appliances, the 65va series for 5- or 6-valve appliances, and the 100va series for 8- or higher.  The Philips branded radio receiver model BE-331A, mounts the ECH42, EAF42, EBC41, EL41, and AZ41 valves, powered by an F2589 referenced transformer with the following windings: 280-0-280v to 60mA, 4v-1A, and 6.3v-2.5A. total 54th.  The recommended transformer to replace it will be the 17031 since the lower model, with the same high voltage value, the 17051, is limited in current in both high voltage and filament winding.  It will be able to be mounted upright like the original Philips brand. As the materials used in the manufacture of these transformers are of the best quality and the design conforms to current regulations, the voltages are more stable, the difference between the vacuum or loaded voltage being much lower than in the old ones, which used finer threads and windings with many more coils negatively affecting the strength of the windings.  Less resistance there will be less voltage drop in them and as a result less heat dissipation.  Taking as an example the Philips receiver mentioned above, this one requires high voltage for the 280-0-280v grinder at full load and the original transformer supplies 295-0-295v in vacuum, dropping 15V when applying the load.  The recommended transformer, reference 17031 provides 280-0-280v in vacuum and will hardly vary at full load as you will only be required 60mA when you can provide 90mA.  Antique valve-powered appliances generate a lot of heat, which is dissipated by the lamps themselves and resistive components.  A proof of the goodness of the materials used in the construction and calculation of these transformers is the working temperature that does not exceed 40oC, well below what is required by the standard that accepts up to 60o.