The use of non-radioactive electron sources for ionizing the target analytes in Ion Mobility Spectrometers (IMS) can lead to new application options. For example, our electron source can be operated in a fast pulsed mode. By optimizing the geometric parameters and developing fast control electronics, we can achieve very short electron pulses for ionization with high intensities, and an adjustable pulse width of down to a few nanoseconds. This results in small ion packets at simultaneously high ion densities. By omitting the separate reaction chamber the ion packet can be generated directly at the beginning of the drift tube with only slight reduction in resolving power. Thus, the complex and costly shutter mechanism and electronics can also be omitted, which leads to a simple low cost IMS-system with a pulsed non-radioactive source, and a resolving power of 70 to 80.