CEO, Digital Power Systems
What Are Power Supplies?
Power supplies convert the unregulated voltage of the mains into a form suitable for consumers. Typically this is a DC voltage, though in LED drivers it can also be a constant current.
The History of Power Supplies
Originally, a power supply consisted of an iron-core transformer with a bridge rectifier. In the beginning, tube rectifiers were used (from around 1920), which were then replaced by selenium, gallium, and finally silicon diodes (from around 1960).
By using high-frequency transformers instead of 50 Hz transformers, power supplies became increasingly compact (in the consumer sector from the 2000s). The new switching frequencies in the 100 kHz range enabled significantly smaller form factors. At the same time, integration progressed: initially, controls were built using operational amplifiers alone, before semiconductor manufacturers integrated the technology into ICs.
The Innovation Driver: Semiconductor Technology
80% of recent innovations in switching power supplies are based on advances in semiconductor technology:
- SiC and GaN: New materials with improved component characteristics
- Faster switching frequencies in the MHz range enable even more compact power supplies
- Powerful microcontrollers available for a few euros enable digital control
- New topologies: Some dispense with the mains rectifier; resonant topologies avoid switching losses
Efficiency - More Than Just a Number
Power supply efficiency has improved from an initial 60% to today's typical 95%. The main benefit for the user: less heat is generated - and heat that is not generated does not need to be dissipated.
Digitisation as an Enabler
Another megatrend is the collection and analysis of data. By using processors, highly dynamic control systems can be built. Eigenvalue controllers enable rise times of less than 1 ms.
Digital power supplies can also cover a wide output range - similar to solar inverters, which offer 98% efficiency over a broad load range.
Software Defined Power as an Opportunity
One hardware platform - many possibilities! Similar to the component strategy in the automotive industry.
The obvious approach is to offer hardware as a base platform that can then be customised through software. For example, a single AC/DC unit could be configured as either a DIN rail power supply or an LED driver.
Semiconductors as a Strategic Component
New processor generations such as RISC-V offer ever more computing power at favourable prices. Initiatives like OpenROAD could make it economically viable to produce even smaller quantities as custom ICs.