Total current measurement interrupts detection method in automotive bulbs circuits

Identification of interruption in automotive bulbs circuits by total current measurement method seems very attractive. This method allows on application the least length and weight wires in automotive electric network. These savings have special meaning in mass production. Due to less connections number increases reliability, too. Basing on electrical schematic general diagram has been described total current measurement interrupts detection method in automotive bulbs circuits. It has been pointed at sensibility on supply voltage value changes range of this method. It has been described bulbs’ main properties. As an analysis example has been chosen the most exacting from the possibilities of total current measurement method indicator lamp circuit. Besides supply voltage change, there are not equal load resistances in this circuit. This causes different bulbs' electric current values. It has been computed failure detector’s electric current values at minimal and maximal voltage in vehicle network. It has been analyzed proper working circuit likewise interruptions in bulbs' 21 [W] and 5 [W] circuits. It has been found that at accepted establishments correct and univocal interruption detection in 21 [W] bulbs is possible in full range of changes supply voltage. Detection of interruption in 5 [W] bulbs is possible only in part of range of changes supply voltage.