Turning a 1250 V Drive Bus into Safe, Stable Control Power

Project in a Nutshell: Promwad built an NDI-based software solution for a European manufacturer of professional broadcast equipment to stream and record high-resolution camera video with minimal delay. We integrated cameras from multiple vendors and made the system easy to scale from one camera to multi-camera setups. The platform provides a transparent control layer for operators and a separate module for reliable camera management. It delivers consistent video quality suitable for live production workflows. The client received a solid foundation they can reuse and extend for new camera models and production scenarios. 

Client & Challenge

A European developer and manufacturer of systems for high-speed industrial machines approached us. For the next version of the product, the client needed an isolated DC/DC converter operating at high voltage. Two requirements are critical for such an architecture: 

• galvanic isolation between the high-voltage power section and the control electronics; 

• stability at input voltages up to 1250 V DC and transient processes typical for drive technology. 

The risks associated with implementation presented an additional challenge. In high-voltage converters, circuit calculations alone are not sufficient. It is necessary to ensure stable power switching and rectification in PWM control mode in advance, and to implement the solution on a board with appropriate insulation rated for 3000 V, taking into account safety requirements and operating conditions (OVC III, PD2, IP21). Otherwise, problems will arise during integration, including unstable operation, false triggering, and safety risks. 

The project faced practical limitations: the client lacked resources and expertise in high-voltage power electronics, so it began with consultations. An engineering team was needed to quickly bring the circuit and board to a working revision and confirm stability at high voltage.

Solution

We developed an isolated HV DC/DC converter as a separate power stage between the HV DC link and the controller power domain. The converter accepts a wide-range HV input, generates a stabilised isolated output voltage and protects the control electronics from the characteristics of the power bus.

During development, we systematically eliminated risks that typically arise during HV converter integration: the stability of the power key driver during high-voltage transients and the stability of rectification during asymmetric PWM pulses. These two components determined the reliability of the entire stage, so we brought them to a stable mode through separate engineering iterations.

Business Value

For the client, this project was not just about redesigning a power stage — it was about removing a bottleneck that was slowing down product evolution. By stabilising the high-voltage DC/DC architecture and validating its performance under real operating constraints, we eliminated key technical risks before the pilot phase.

At the same time, their internal team stayed focused on core AMB technology, while we closed the gap in high-voltage power electronics. The outcome is a more robust product architecture and a clearer path to industrial deployment.

More of What We Do for Power Electronics

• Power Electronics Design: explore our comprehensive range of power electronics design services for low-voltage, medium-voltage and high-voltage applications.

• DC/AC Servo Drives: check out case study is about developing a SIL 3-ready AC/DC servo drive for safe, scalable mass production.

• Power Electronics for Fuel Cell Systems: find out more about our research into how power electronics ensures the stability of fuel cell systems and their readiness for practical application.