Switch-off delay

This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

The switch-off delay is the time span from the beginning of the continuation of the maintenance of the voltage of a stationary useful signal , accompanied by the action of the response value of the action variable of the trigger signal belonging to the switch (which can technically be implemented as a digital switch-off delay element) until the activation of the " Switching off "after a delay time at the useful signal, an achievement which ends the maintenance of the voltage of the stationary useful signal and leads to a falling signal curve (in the case of a digital circuit, a signal edge falling to a low signal). ${\displaystyle {\mathcal {}}y(t)}$ ${\displaystyle {\mathcal {}}x(t)}$

${\displaystyle \Delta t_{AV}=t_{y_{_{_{2}}}}-t_{x_{_{_{1}}}}}$

A switch-on and switch-off delay as implemented with digital switch-on and switch-off delay elements

Realized with a digital switch-off delay element, this means nothing other than that the falling signal edge of a trigger signal triggers a falling signal edge on a useful signal delayed by the time span . ${\displaystyle {\mathcal {}}x(t)}$ ${\displaystyle {\mathcal {}}\Delta t_{AV}}$ ${\displaystyle {\mathcal {}}y(t)}$

The term comes from electrical engineering .

Examples of switching and compensation processes from practice

When the self-production of boards in exposing a specific duty is UV - lighting prescribed. In this case, the relay in the lamp circuit should only remain switched on for a short time after the supply voltage has been applied and then automatically drop out again. This is known as the fall-out delay.

With stereo systems, on the other hand, there is often a loud crackling after switching on, which is caused by charging processes in the amplifier stages. This can be avoided relatively easily by only switching on the loudspeakers a short time later than the device power supply . In this case, it is about the delayed switching on of a relay, which then remains permanently picked up. This is the switch-on delay.

The perfect delay circuit should cover both cases, i.e. either remain switched on for a short time or switch off after a short time. You need a time-determining element and a switching stage. With the relays this will normally be the changeover contact. If you connect an (initially discharged) capacitor to a constant voltage via a resistor , current flows into the capacitor and its charging voltage increases.

Individual evidence

1. ↑ ^{a b c} Klaus Beuth: Digital technology. (Electronics, Vol. 4) 7. revised. Ed., Vogel, Würzburg 1990, ISBN 3-8023-0584-1 , p. 230