This design was chosen for its relative simplicity compared to the more efficient but more complex pushpull output stage, in which output tubes are configured in matched pairs. Academic formulas for calculating the design of output trannys is available in many text. The peak is the rms voltage times the square root of 2. An online three phase transformer calculator to find the current in different power units. Addchange button for addingchanging wanted voltage and. Transformer calculator cnet download free software. How to calculate the required capacity kva rating or. Complete software package for transformer design optimization and economic evaluation analysis article pdf available in materials science forum february 2014 with 11,303 reads.
Understanding impedancein audio transformers transformers provide galvanic isolation. Professionals with experience in transformer assemblies use the computer program to calculate the number of coils and wire thickness. K agarwal under the title of principles of electric machine design. Afaik, there is no available output transformer calculator program available anywhere so that you enter tube type, mode of operation, output power maximum, and after clicking calculate, all the winding details appear on a sheet you can take to a person who knows how to read the diagram and wind the opt without asking you to not come back.
So i want to know, how to calculate turns, impedance and watts. A singleended power amplifier is created by removing the lower tube and the lower half of the transformer. Since for power amplification it is usual to use pentodes or beamtetrodes, which produce predominantly odd harmonics, we can expect all. To separate the high voltage and match the speaker impendance with the tube impendance we need audio grade output transformer. Set up the circuit in ltspice and couple the inductors and you can play around and see what happens. Output trannys contribute most of the distortion in a valve amp and have a limited bandwidth. Max apparent power rating loading percentage output current current of protective circuit breaker short circuit fault current short circuit. A flyback transformer design is far more complicated than one.
For tubes this is wrong the real output transformer cannot pass very low frequencies without some distortion. To increasedecrease the alternating volts in electric power, transformers are used. For single ended amplifiers with opt idc flow in one direction only. Magnetic builder magnetic design software, inductor and. Calculating output transformer impedance sarris custom. Input voltage,maximum flux and how to maximize voltage current and output stability you visit. Checking an unknown output transformer we can now use this knowledge to determine the impedance of any unknown output transformer. If youre serious about this, consult flanagans transformer design books for charts and graphs or other transformer references. How to calculate the overall gain of an audio amplifier with and without negative feedback. Few people working in transformer winding companies have a knowledge of electronics or valve amps. Morse view is an open source software project to convert audible morse.
Grand stack version with more iron, thus more power, more bass and finally more tone. For homebrew projects, the best option is to construct those transformers by ourselves and this script helps to calculate winding parameters for those transformers. Software creates total practical variants that satisfies limits and orders of user. Opt design wikibooks, open books for an open world. Transformer calculator kva calculator full load amps. I want to make an audio output transformer for tube amplifier. After creating inputs data of transformer, software create detailed inputs according to data base setups that included in. Transformer and short circuit calculator that provides base load current and short circuit currents for identified ge transformers. This is a sample kva calculation and does not take into account possible special load requirements, such as found with motors or some medical equipment, or other specialty applications. How to calculatefind the rating of transformer in kva. The objective of this project is to develop an output transformer for singleended tube amplifiers with. With a set of three tools command line interface based dpicli, a simple, fixed. Enter the transformer rating and select the appropriate unit. A toroidal transformer is a transformer shaped like a doughnut.
Output transformers transformers passive components. This af output transformer calculator script is written using python and it. Experience or comparison works best, though, and is what the pros do in practice. There are a number of factors in transformer design that influence the size of the core and hence set the size in one way or another. Lewis research center summary users of this program are relieved of most computational details, while maintaining control over most engineering decisions, in the design of toroidal transformers for use in parallel inverter circuitry. I cover how to calculate the reflected impedance of the output transformer secondary onto the primary. Youre going to have a really hard time just stumbling upon a transformer thats suitable to use as an ot in a single ended amp.
When current passes through the primary coil, it creates a magnetic field which then acts as an inductor to create voltage in the second coil. Once powered, the winding generates a magnetic field and stores. Heres a handy c program for the design and verification of transformer characteristics. Currently tdpro is available from 16kva to 5000 kva, 3 phase, up to 36 kv, oil cooled with layer layer, layer co, foil layer, disc disc etc windings, facility of printing complete gtp. Schematic of the loftinwhite singleended tube amplifier. All we need to do is determine the turns ratio of the transformer, and with that information we can calculate what impedance will be reflected back to the primary with a given load on the secondary. Select the number of phases from the dropdown menu. E design opt for 1 x el34 pentode with or without cfb. This af output transformer calculator script is written using python and it works with most of the commonly available python interpreters. Pdf complete software package for transformer design. If the fulcrum is in the middle, like in a seesaw, than neither the voltage nor the current will alter from the primary to the secondary. Calculation of output transformers the output transformer is probably the most expensive part in the amplifier and something you have to live with if you like classic tube amplification. This limit defines as setups for software according to workshop limits or other matters. It also determines the turns ratio and type of transformer.
Andrea ciuffoli and his audio design guide webpage. Works for fender champ, tweed champ, blackface champ and tweed princeton 5f2a. If you dont know anything about assembling transformers, please dont use calculations from this program for building your own transformer. Building a tube amp, how to calculate output transformer. Are you looking for the best transformer calculator software for your next project.
If you need assistance with circuit protection devices such as fuses or breakers, or wire sizing, please consult a licensed electrical contractor or electrician in your area who will be familiar with state and local codes. Distribution transformer calculator free download and. Audio transformers the audio design guide lundahl transformers. Calculating output transformer impedance how to calculate the output transformer impedance of an opt with unknown values working with tube amps you may need to calculate the output transformer impedance especially when we have an old transformer or a transformer with unknown values. Download transformer calculator coils and wire thickness at. The design of an audio transformer operating over a 20. Transformer winding turns and voltage ratio calculator v1, n1, v2, n2. The iron core with the coil of wire is also called the winding. Valve amp manufacturers purchase trannys from transformer winding companies. Magnetic builder magnetic design software, inductor and transformer design tool poweresim is a free webbased software providing power supply smps design, transformer design, magnetic design, loss analysis, thermal analysis, waveform analysis, mtbf analysis, bom building, dvt analysis and optimization of power supply smps click to try poweresim. Transformer capacity calculator three phase transformer. This excel sheet is a guide to find the appropriate lundahl output transformers to a certain tube.
A transformer is essentially a pair of coils wrapped around iron cores, which are called primary windings and secondary windings for input and output, respectively. How to calculate electrical transformer output sciencing. Select your primary and secondary transformer voltages and the kva rating and let this calculator report the primary and secondary currents of the transformer. Another cause of unbalance in the transformer is dynamic unbalance between the tubes, this will show itself as even order distortion even though the tubes are dc balanced and if dynamic unbalance is large the transformer can saturate on signal peaks which will limit low frequency output.
Transformer design software integrated engineering software. Then i cover the different speaker combinations and. Audio output transformers are heavily used in a vacuum tube and some. To calculate the reactive power due to just the shunt magnetizing impedance, use %load as no load. Toroidal transformer design program with application to inverter circuitry by james a. Such transformers need to be specially designed with an air gap, and they often have very high impedence and therefore turns ratios. The driver sees the loads in parallel or, neglecting winding. Audio and impedance matching transformers are similar in design to low. Transformer reactive power loss calculator the calculator below can be used to calculate reactive power consumption in transformer at full load and rated voltage. This 4 turns per volt is from standard table for small transformer design calculation listed in book by r. All the output transformers can be divided into two groups. Transformer calculation is program for calculating number of coils and wire thickness at transformer.
Below are the two simple formulas to find the rating of single phase and three phase transformers. Secrets of output transformers dali technical sales. With this coil calculator you can design and calculate the properties of a coil or transformer. Enter the parameters in the yellow coloured fields, and then click the calculate buttons. Using a 50 kva single phase transformer as a starting.
This transformer calculator helps you to quickly and easily calculate the primary and secondary fullload currents of the transformer. Amperage provided for a given kva can be determined by similar techniques. It has two types, single phase and three phase transformer. Transformer calculation software electronic circuits. Simple transformer driver for stax electrostatic headphones. Download transformer calculator coils and wire thickness. Transformer winding is an extension of the fitting and turning industry. Afaik, there is no available output transformer calculator program available anywhere so that you enter tube type. It is important to note, however, that these solutions are best only for those experts who have knowledge and experience with assembly transformers. Audio transformer is the primary part of a tube amplifier which generates an electromagnetic field. Smps schematic transformer calculator stack exchange. Aug 3, 2015 transformer calculation is program for calculating number of coils. The turns ratio between the input and output wire coils provides either an increase or a. How to calculate the required capacity kva rating or amperage capacity for single and three phase transformers.
If you connect only the primary wires of a transformer, and measure the inductance, no energy leaves through any secondary windings, so the thing looks like and. Program quickly calculates transformer design parameters. It has a round iron core with a coil of insulated wire wrapped around it. If you have some experience in assembling transformers, then this program is perfect for you. The sound produced by a singleended amp is rather unique. For single ended transformers it is the same rule impedance to impedance. Audio transformer and impedance matching transformer. Poweresim free smps switching power supply transformer.