Abstract: An endurance testing system is configured to test endurance of a first detecting apparatus. The endurance testing system includes a second detecting apparatus, a movement module, a processor, and a storage module. The movement module includes a first inductive object and a second inductive object. The processor is connected to the first and second detecting apparatuses, and the movement module, for controlling the movement module and counting a first number of times the first detecting apparatus detects the first inductive object, and a second number of times the second detecting apparatus detects the second inductive object. The storage module is connected to the processor, for storing the first and second numbers of times from the processor. The first detecting apparatus fails the testing upon the condition that the first number of times is not equal to the second number of times.

Abstract: An exemplary metal detector includes a detecting circuit, a SCM, a converting circuit, and a cymometer. The SCM cooperates with the detecting circuit to generate a current signal with a specific frequency, the converting circuit transforms the current signal received from the SCM to a voltage signal, and the cymometer displays a value of a frequency of the current signal according to the voltage signal. When the detecting circuit detects a metal nearby, the value of the frequency of the current signal displayed on the cymometer changes.

Abstract: A luminous intensity measuring device includes a photoresistor, a number of voltage-dividing resistors, a plurality of comparators, a micro control unit (MCU), and an indicator. The photoresistor is connected to a current-limiting resistor in series between a direct current (DC) power supply and ground. The voltage-dividing resistors are connected in series, and together are connected parallel to the photoresistor and the current-limiting resistor located between the DC power supply and ground. A non-inverting node between the photoresistor and the current-limiting resistor is connected to the non-inverting input terminals of the comparators. The inverting terminals of the comparators are respectively connected to inverting nodes between every two adjacent voltage-dividing resistors. The output terminals of the comparators are connected to the input terminals of the MCU. The indicator is connected to the output terminals of the MCU. The MCU controls the indicator to indicate luminous intensity.

Abstract: An endurance testing system is configured to test endurance of a first detecting apparatus. The endurance testing system includes a second detecting apparatus, a movement module, a processor, and a storage module. The movement module includes a first inductive object and a second inductive object. The processor is connected to the first and second detecting apparatuses, and the movement module, for controlling the movement module and counting a first number of times the first detecting apparatus detects the first inductive object, and a second number of times the second detecting apparatus detects the second inductive object. The storage module is connected to the processor, for storing the first and second numbers of times from the processor. The first detecting apparatus fails the testing upon the condition that the first number of times is not equal to the second number of times.

Abstract: A metal detecting apparatus includes a sensor, a current signal outputting circuit, a transforming circuit, and a micro processing unit (MPU). The sensor is configured to sense metal objects in close proximity. The current signal outputting circuit is configured to generate alternative current signals. The alternative current signals are converted to digital voltage signals via the transforming circuit. The MPU is configured to obtain a specific frequency value of the alternative current signals according to the digital voltage signals. When the sensor senses a metal object in close proximity, the specific frequency value obtained by the MPU changes. The MPU is configured to determine if a metal object has been detected by determining if the obtained specific frequency value has changed.

Abstract: An exemplary metal detector includes a detecting circuit, a SCM, a converting circuit, and a cymometer. The SCM cooperates with the detecting circuit to generate a current signal with a specific frequency, the converting circuit transforms the current signal received from the SCM to a voltage signal, and the cymometer displays a value of a frequency of the current signal according to the voltage signal. When the detecting circuit detects a metal nearby, the value of the frequency of the current signal displayed on the cymometer changes.

Abstract: A luminous intensity measuring device includes a photoresistor, a number of voltage-dividing resistors, a plurality of comparators, a micro control unit (MCU), and an indicator. The photoresistor is connected to a current-limiting resistor in series between a direct current (DC) power supply and ground. The voltage-dividing resistors are connected in series, and together are connected parallel to the photoresistor and the current-limiting resistor located between the DC power supply and ground. A non-inverting node between the photoresistor and the current-limiting resistor is connected to the non-inverting input terminals of the comparators. The inverting terminals of the comparators are respectively connected to inverting nodes between every two adjacent voltage-dividing resistors. The output terminals of the comparators are connected to the input terminals of the MCU. The indicator is connected to the output terminals of the MCU. The MCU controls the indicator to indicate luminous intensity.