In order to understand the condition of ignition of an electric fusehead, the effect of pulse height and duration of the firing current on the minimum ignition energy (MIE) has been investigated by experiments and numerical calculations. The experimental results show that MIE is strongly dependent on the height of the single square wave of the firing current. Numerical calculations were conducted to estimate the temperature distribution of the bridgewire considering an effect of heat losses from the bridgewire to the surroundings. As the results, it is found that the calculation can well reproduce the minimum time for ignition and MIE obtained by the experiment. In addition, the maximum temperature in the center of the bridgewire play an important role in determining ignition.
electric fusehead, ignition energy, firing current, ignition temperature