Electronic device circuit breakers

Electronic device circuit breakers actively limit short-circuit and overload currents to 1.25 times the nominal current. This protects the power supply unit against currents which are too high and associated overloads, and prevents the output voltage from interrupting the switched-mode power supply unit.

It is therefore possible to virtually fully plan the connected load of a DC voltage power supply. Longer cable paths between the power supply unit and load are possible without negatively impacting the shutdown behavior.

Design

Electronic device circuit breaker

Key:

On/off switch (reset)
Status indicator
Green = connected through
Yellow = current limitation
Red = switched off
PCB with current sensor

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Function

The integrated sensor continuously measures the current applied and switches off within approx. 100 to 800 milliseconds in the event of an overload current or short circuit.

In contrast to thermal and thermomagnetic device circuit breakers, these protective devices switch electronically via a transistor. The circuit is not electrically interrupted with a mechanical switch contact.

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Circuit diagram

Circuit diagram of an electronic device circuit breaker

Key:

1. Power in (line +)
2. Power out (load +)
a. Reset in
b. GND (ground)
c. Status out

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Tripping characteristic

Tripping characteristic of an electronic device circuit breaker

Even in the case of high cable resistance, electronic device circuit breakers trip a few milliseconds after a short circuit. In the event of overload, the current is a maximum of 1.25 times the nominal current.

Key:

t = switching time (in seconds)
xl = multiple of the nominal current/tripping factor
1 = tripping minimum 1.05 x nominal current
2 = shutdown time maximum of 800 ms (nominal current-dependent)
3 = shutdown time minimum of 80 ms (nominal current-dependent)
4 = tripping maximum of 1.45 x nominal current
5 = current limitation with 1.25 x nominal current

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