Electrical and Electronics Commons^™

Automating The Screening Of Microphonic Defects In Automotive Radio Receivers, Chin-Leong Lim

Chin-Leong Lim

Microphonics are unwanted electro-acoustic effects in electronic equipment caused by mechanical vibration. Vehicular radio receivers are particularly susceptible due to their traveling over uneven roads, e.g. potholes and bumps. As microphonics influence customers’ perception of product quality, manufacturers actively seek to sieve out receivers exhibiting the worst manifestation of this defect. The IEC 315-4 standard for FM broadcast receivers mandates screening for "unwanted acoustic feedback" by tapping on the receiver housing and then listening for the tell-tale ringing noises at the audio output, i.e. speakers or headphone. However, this subjective method requires trained workers and even then, the repeatability can …