WEBVTT
Kind: captions
Language: en

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Electronic devices intended for sale

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must be subjected
to various tests beforehand.

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These include immunity tests during which

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the function of the device under test

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may be disturbed.

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But how does the interference work?

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To determine this, small devices

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such as pulsers can be used.

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These make it possible

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to specifically examine

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small areas of the assembly

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and find the cause of the interference.

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Pulsers work as a field source.

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They generate fields at their tip

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that are similar to the fields

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generated by
standard burst and ESD generators.

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As a result, they can affect electronic devices.

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The P11 pulser acts as a magnetic field source.

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The toggle switch can be used

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to switch between single pulses –

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each press of the 'ON' button

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generates exactly one pulse –

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and a 5 Kilohertz pulse train.

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The intensity of the pulses
can be changed continuously.

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The polarity of the field

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can be changed via the front toggle switch.

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A light emitting diode signals

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a necessary battery change.

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Analogous to this, the Pulser P21

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works as an electrical field source.

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It offers the same
setting options as the P11 Pulser.

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Langer EMV-Technik has developed demonstration boards

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to demonstrate the operation of the pulsers.

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The demonstration board SF11 and the pulser P11

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are suitable for demonstrating magnetic coupling.

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Signal 1 is selected via switch S2.

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Now the pulser working as a magnetic field source

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is passed over the board.

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If the pulser is above the gap,

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the magnetic field emitted by it

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penetrates the gap

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and induces a voltage

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in signal line 1.

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The circuit connected to signal line 1

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processes this voltage as a signal,

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switches on the relay

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and thus symbolizes a functional fault.

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To prevent interference,

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the gap can be covered with copper.

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Alternatively, switch S2 can be toggled:

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Signal 2 is completely backed up with GND

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and thus much more interference resistant than signal 1.

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The electrical coupling can be shown

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on the demonstration board SF21

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with the pulser P21.

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If signal 1 is active,

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it can be influenced by an electric field

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emanating from the pulser P21.

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Signal 1 is partially outside the GND area

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and is therefore particularly sensitive.

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In contrast, signal 2 is

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completely connected to GND

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and is therefore much more
immune to interference.

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The demonstration boards

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SF11 and SF21 of Langer EMV-Technik

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are suitable for demonstrating
immunity phenomena.

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For this purpose, a variety of
different EMC measurement devices

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such as ESD and burst generators
from all manufacturers can be used.