Purpose of this master’s thesis is a development, testing and production of a switch-mode power supply for the diesel engine glow plugs. The device uses source of the electrical power in the vehicle and correctly supplies the energy to the four glow plugs for diesel engines Hidria PSG, located in the motor block. Computer in the vehicle gives the signal when the supply of the glow plugs is needed, device gives a feedback to the computer about the supply status.
At first, construction and operational characteristics of glow plug for diesel engines with pressure sensor Hidria PSG were investigated. Using the results and considering the customer’s wishes, a list of design requirements for switch-mode power supply was made.
The power supply has to operate at input voltages from 16 V to 32 V. Each of the two outputs powers two glow plugs Hidria PSG with a constant voltage of 4,4 V and maximum current of 15 A. Outputs are active only when a 32 Hz square signal with 7 V amplitude and 50 % duty cycle is generated by the computer in the vehicle, connected to the ST connector. Diagnostics signal is high if both output voltages are in 10 % range of the pre-set voltage. If an overcurrent is detected, controller switches the output off. In this case the second output is still active, diagnostic signal is low. Housing of the product and the connectors were defined before.
After the research of available controllers, decision to use MAX17559 with current mode control was made because it was recognized as the most suitable for this product. Having in mind the design requirements the schematics in Altium Designer and behaviour simulation in EE – Sim SE simulator was done. All the components needed for the switch-mode power supply were chosen. Printed circuit board was made and housed. Behaviour, additional functions and radiated emissions of power supply were tested.
The result is developed and produced A prototype of switch-mode power supply for the diesel engine glow plugs Hidria PSG, which was sent to the buyer to confirm the functionality of the product.