What is it?

This kit was designed in Germany and published in the ELV magazine in 2002. It's purpose it to check and detect abnormal states or outages of impuls signals from digital control equipment. The device continguously monitors the input signal ( with a 3V - 15V level ), and verifies its impuls and pause durations in the range from 1 msec to 999 seconds. So both the pulse widths and frequency are guarded. The duration limits of the low and high levels can be adjusted independently of each other. If the signal falls out of the set valid window, the alarm output is activated and the event counter display is incremented. The device operates with a 9 Volt battery or an external 9 - 15 Volt AC adapter (option).

This is a kit by ELV, the german electronics magazine !!

Beware : The manual and circuit description included with the kit is in the german language. You should be able to understand or translate that original, as no English translation was published. The brief description that is still online is under the link.

What makes it special?

The function of the assembled test instrument is unique in that it is able to detect and debug exceptions of the input signal unattended. So it is usefull for monitoring over long periods : hours or continguously ( 24 / 7 ) .