Skip to main content
Biamp Systems

Creating a momentary logic pulse

Most logic signals in Audia and Nexia are latching (toggle) signals that stay in the same state for most of the time. They're either on or off. In some instances though, we need to use these signals to trigger a brief, momentary logic pulse signal. This article explains how to do that with some simple logic. 

Momentary trigger on any change

The logic circuit described below will generate a logic pulse whenever the input signal changes state (i.e., it will trigger on both a low-to-high transition and a high-to-low transition). Wire a Logic Delay block and an XOR Gate to your logic signal as shown below:

The on and off time in the Logic Delay will dictate how long the trigger will be. For instance, if you set both to 2000ms, when the steady state goes on, we will get a momentary logic signal (high) lasting 2 seconds. The same thing will happen when the steady state goes off.  You can change the values of both to suit your needs. 

Momentary trigger on rising edge only

The above circuit generates a momentary trigger on either high or low signal.  However, sometimes you only want the logic pulse to trigger when the input signal goes from low to high.  There are several ways to accomplish this, and the logic circuit below is one of the more straightforward methods:

In this case, a momentary logic trigger lasting 2 seconds will be generated only when the input from the source goes from low to high. When it goes back low, nothing will happen.

  • Was this article helpful?