“Horses harnessed to a chariot run faster than singly, not because they can move through the air more easily with their combined efforts, but because they are inflamed by competition and rivalry with one another” – Plutarch

I, one of those gray-haired ones, came across some statistics on power supply module sales. In a succession of a dozen brands, one firm in particular stands out. It’s a firm called TRACO POWER, and it’s either first or second in all categories. It sticks out. Maybe this company has gathered a group of talents and continues to make technological, circuitry, manufacturing and marketing miracles for decades? After all, “borrowing the good is not a sin”, as my teacher urged the developers.

Therefore, our team of developers and engineers chose three very interesting power supply modules, on the basis of which TRACO POWER already makes products today – for 12 W, 30 W and 60 W.


The eye-catcher is immediately impressed by the original red-and-black design of the labels and cases! In terms of specifications, we are especially interested in TRACO’s latest development, the 60 W module in 2 x 1″ format (the drawing shows a close match for the 40 W model). We also would like to pick up a very popular 80…120W model, but we could not find such a model in TRACO nomenclature with small dimensions, not bigger than 1/4 BRICK.

After measuring the parameters of these modules we have opened them, decided on the circuitry and ECB.

On the one hand we can see seemingly simple circuit design of inversion converters, although in the literature of the early 21st century it was always claimed that at low output voltages even at 20-30W power losses, including those caused by leakage inductance in the inversion converter will lead to a strong decrease in efficiency. Measurements for TRACO, however, show that at an output voltage of 5 V for a power rating of 60 W, the efficiency is over 91%! And it is achieved not only by the synchronous rectifier, but also by unique design and technological solutions of transformers, starting devices and PWM controllers, as well as by isolation barriers for synchronous rectifiers between primary and secondary sides based on SILICON LABS chips.

I also wondered why in some cases a planar transformer with printed windings was used, and in some cases the developers left a wire winding on a low profile ferrite core. Gradually it came to be understood: the circuit decisions and the choice of ECB were made on the basis of very difficult optimization and modeling according to electrical, design and technological and marketing criteria. Another big plus for the developers of TRACO POWER and of course respect.

We were pleasantly surprised by the absence of cheap Chinese ECB – we use standard well-proven high-level components, and of course not cheap. Indeed, without a miracle here – how do the developers and production can fit into a fairly affordable price?

Conclusion: TRACO POWER really had a talented team working with these products, for many years creating new generations of high performance power modules.

But we ourselves, the AEPS-GROUP team (by the way, this stands for Alexander Electric Power Supplies Group) did not want to go far behind and we took a risk.

Our generation of mass-produced DC/DC modules JETDi20 (DIP24), JETDi30 (1×1 inch), JETDi100 (1/8 BRICK) and JETDi150 (1/4 BRICK) in copper thin-walled housings without mounting holes were created thanks to the invisible help of the TRACO POWER team (too bad – they don’t know that!). The picture shows these new models.

Of course, our circuitry and design solutions turned out to be different, but our goals were also to achieve good performance under more difficult operating conditions. These power supply modules are direct competitors to TRACO POWER modules, replacing them not only in common industrial equipment, but also in equipment for demanding applications. The latest 150W JETDi150 (1/4 BRICK) model is unmatched by TRACO; the development of this module proved to be a real challenge, but the resulting performance was well worth the resources expended.

The positive results achieved with the JETDi series have encouraged our AEPS-GROUP team. For particularly heavy applications, the circuitry of the power supply modules of the JETDi series were accommodated without altering the overall dimensions in reinforced cases with fixing holes made in the circumference of the case. We called these modules: JETDiR20, JETDiR30, JETDiR100, JETDiR150.

What are the differences and how are the above mentioned series of new power supply modules JETDi and JETDiR similar?

Differences in enclosure design properties while matching dimensions:
JETDi have thin-walled stamped copper housings without mounting holes, JETDiR modules are in flangeless design, in VICOR – BRICK standard housings, and have mounting holes in the housing outline. Hence the different applications. The JETDi are actually attached only by pins soldered into the circuit board, which prevents them from being used in applications with large vibrations and shocks. The JETDiRs are made in milled reinforced aluminum housings with internal stiffeners and are specifically designed for any class of hardware, including high vibration and shock applications.

There are also big differences in temperature resistance between the two series.
The fact is that for the JETDi, as recommended by TRACO POWER, a special ribbed or needle design can be used as a heat sink, which is attached to the back of the module with clips. This solution has a very low efficiency in non-blowing structural volumes, and the mechanical stability is further reduced. The JETDiR modules are freely attached to the metal surfaces of the equipment and are therefore very temperature resistant.

Both series are designed for electrical DC mains, typical for distributed power supply systems using battery support: 12 (10.2…15) V, 12W (10.2…30) V, 24 (20…30) V, 24W (20…60) V, 27 (20…40) V, 27W (15…50) V and 48 (36…75) V. The numbers in the module names indicate the maximum output power of the module in watts, to ensure long-term reliability, the load factor of these modules should be chosen in the range 0.7…0.8. That means that the modules of this series, labeled 20, 30, 60 and 120 watts, are optimized for average power of 15, 20, 50 and 100 watts respectively.

Electrical advantages: All JETDi and JETDiR single-channel modules contain synchronous rectifiers up to an output voltage of 27V, which greatly increases their efficiency. The possibility of implementing the two-channel output with galvanically isolated channels gives a unique possibility of circuit implementation in all four possible variants: independent two channels, parallel connected channels, channels in series to obtain the high-voltage output and the output with a midpoint.

Design advantages: The JETDi and JETDiR series modules are very small in size, which, combined with their high efficiency, allow for an unprecedented design power density from 49W/in3 to 106W/in3. Given that all components are structurally bonded to the housing and encapsulated in a rigid, thermally conductive compound the resistance and robustness to mechanical stress is good. LP designs are available with a reduced profile of 10-20%. This planar design improves the compatibility of modules in hardware.

Modules of this series in most cases can operate without additional heat sink, having increased efficiency up to 90%. On request, maximum operating temperature on the housing is allowed up to -60…+130 °C.

On our website we list eleven application groups.

For the JETDi series we recommend applications in areas 4, 5, 7, 8, 9 and 11 that are characterized by a lack of significant mechanical stress – shock and vibration, such as drones, balloons and gliders, weather probes, all types of ground transport – railway locomotives and wagons, cars. JETDi modules are quite optimal for telecommunication facilities, supercomputers, radars and display screens in external environment.

For the JETDiR series, which has a very good resistance and robustness to mechanical impacts, we allow a much wider range of applications. These modules are optimal for use in all applications 1 – 11 listed on our website – for flying objects at altitudes up to 15 km in unpressurized and unprotected compartments: aircraft, drones, rockets, helicopters, flying balloons and gliders, meteosondes. In all types of ground transport – railway locomotives and wagons, cars, tracked vehicles. JETDiR modules are optimal for telecommunication facilities, in equipment used in mining, for supercomputers, for radars and information display screens in external environmental conditions and finally in very wide ambient temperature ranges – they work in the Arctic and Antarctica, in the mountains at all altitudes and in cold and red-hot deserts, etc.

High efficiency up to 93% allows for an extreme (optional) operating temperature range of 60…+130 °C on the enclosure.

General conclusion: we recommend developers – do not be afraid to compete with the world manufacturers!