DC power line communication based on power/signal dual modulation in phase shift full bridge converters

For intelligent DC distributed power systems, data communication plays a vital role in system control and device monitoring. To achieve communication in a cost effective way, power/signal dual modulation (PSDM), a method that integrates data transmission with power conversion, can be utilized. In this paper, an improved PSDM method using phase shift full bridge (PSFB) converter is proposed. This method introduces a phase control based freedom in the conventional PSFB control loop to realize communication using the same power conversion circuit. In this way, decoupled data modulation and power conversion are realized without extra wiring and coupling units, and thus the system structure is simplified. More importantly, the signal intensity can be regulated by the proposed perturbation depth, and so this method can adapt to different operating conditions. Application of the proposed method to a DC distributed power system composed of several PSFB converters is discussed. A 2kW prototype system with an embedded 5kbps communication link has been implemented, and the effectiveness of the method is verified by experimental results.

Diabetes management in care homes:steps in the right direction?

Aims: Previous research has identified several inadequacies in management of diabetes within care homes many of which were highlighted in Diabetes UK’s report Diabetes in care homes:awareness, screening, training. The aim of this study was to see if this was still the case and to identify specific areas for improvement. Methods: Thirty care homes in Birmingham were invited to participate in the study. Data were collected using a standard questionnaire based on the Diabetes UK national survey of care homes comprising questions relating to screening, self-management, care planning and local authority support. All returned responses were analysed. Results: Responses were received from 20 of the 30 care homes approached. The mean percentage of residents with diabetes in the care homes sampled was 13.7%. None of the homes screened for diabetes on admission and only 5% screened residents annually.80% of homes acknowledged providing diabetes-specific training to staff. Residents in 95% of homes had a medical review in the last 12 months: 70% with a GP, 20% with a diabetes specialist nurse/nurse. 65% of homes provided support for self-management.45% of care homes did not have individualised care plans for residents with diabetes. 35% of managers reported poor support and guidance from their local authority.Conclusions: Improvements were noted in the care provided to individuals with diabetes living in care homes in Birmingham. Aspects relating to screening, individualised care plans and support to care home staff still need attention.