Dual loop

Definition and Purpose of Dual Loop
– Dual loop is a method of electrical circuit termination used in electronic security applications.
– It combines two circuits (alarm and anti-tamper) into one using resistors.
– The purpose of dual loop is to allow the burglar alarm control panel to read the values of end-of-line resistors for zone status.
– It replaced the basic closed-circuit system in the early 21st century due to changes in international standards and practices.
– Dual loop is also known as Balanced EOL (End of Line) resistors.

Functionality of Dual Loop
– In a dual loop system, an inactive detector gives a reading of 2K ohms as the circuit passes through one resistor.
– When a detector goes into an active state, the circuit path is altered and it must pass through a second resistor wired in series with the first.
– This alteration in the circuit results in a reading of 4K ohms, triggering an intruder alarm.
– If the system doesn’t recognize a resistance reading due to a short-circuit or open-circuit, an anti-tamper alarm is triggered.
– Dual loop provides a more secure method compared to the former Double Pole loop.

Advantages of Dual Loop
– Dual loop systems are more secure than basic closed-circuit systems.
– They provide the ability to differentiate between inactive and active states of detectors.
– The use of end-of-line resistors allows for zone status monitoring.
– Dual loop systems comply with mandatory UK standards.
– They offer improved protection against tampering attempts.

Limitations of Dual Loop
– Dual loop systems can still be bypassed by individuals with sufficient knowledge of security alarm systems.
– The effectiveness of dual loop systems relies on proper installation and maintenance.
– If resistors are incorrectly wired or damaged, the system may not function as intended.
– Dual loop systems may require periodic testing and calibration to ensure accurate readings.
– The complexity of dual loop systems may require specialized expertise for installation and troubleshooting.

References and External Links
– Mandatory UK standard for dual loop systems.
– Calculators available for resistors in series and parallel.
– Retrieved information from the Wikipedia page on Dual Loop.
– Category: Analog circuits.
– Hidden category: Webarchive template wayback links.Sources: https://en.wikipedia.org/wiki/Dual_loop