crowbar circuit

An example crowbar circuit is shown to the right.

Many bench top power supplies have a crowbar circuit to protect the connected equipment.

An instantaneous power-supply crowbar circuit will operate too late.

This is commonly called a crowbar circuit.

A crowbar circuit is distinct from a clamp in that, once triggered, it pulls the voltage below the trigger level, usually close to ground.

SMPSs often include safety features such as current limiting or a crowbar circuit to help protect the device and the user from harm.

Although usually the result of a fault, there are cases where short circuits are caused intentionally, for example, for the purpose of voltage-sensing crowbar circuit protectors.

Crowbar circuits are frequently implemented using a thyristor, TRIAC, trisil or thyratron as the shorting device.

A crowbar circuit is an electrical circuit used to prevent an overvoltage condition of a power supply unit from damaging the circuits attached to the power supply.

A Trisil is a type of thyristor surge protection device (TSPD), a specialized solid-state electronic device used in crowbar circuits to protect against overvoltage conditions.

When a circuit must be protected from overvoltage and there are failure modes in the power supply that can produce such overvoltages, the circuit may be protected by a device commonly called a crowbar circuit.

The purpose of the crowbar circuit is to instantly dump the massive electrical charge stored in the high voltage beam supply before this energy can damage the tube assembly during an uncontrolled cavity, collector or cathode arc.

Like most linear beam tubes having external tuning cavities, IOTs are vulnerable to arcing, and must be protected with arc detectors located in the output cavities that trigger a crowbar circuit based on a hydrogen thyratron or a triggered spark gap in the high-voltage supply.

However, many regulators have over-current protection, so that they will entirely stop sourcing current (or limit the current in some way) if the output current is too high, and some regulators may also shut down if the input voltage is outside a given range (see also: crowbar circuits).