Cable testing audio signal generator

It has the following characteristics:

lBy using microcontroller control, the output of the instrument can be adjusted according to different load impedances to achieve impedance matching.

lHigh output power, high output voltage, strong signal penetration, and large detection range.

lEquipped with overcurrent automatic protection function and high reliability.

lEasy to operate.

lEasy wiring.

two technical indicators

lOutput power20W

loutput voltageMAX：200V

lTransmission signal frequency:1kHzsine wave

lSignal transmission mode: continuous/Intermittent optional

lPower supply voltage:AC220V/50Hz

lOperating temperature:-10℃～40℃

three Host appearance and panel description

1. Host appearance

2. Panel Description

① power socket : Built in1A fuse, connected to an AC220V/50Hz socket through a three core power cord.

② power switch : PressPress "1" to turn on, press "0" to turn off, with an indicator light indicating.

③ Output matching adjustment According to the different loads of the instrument, it can be adjusted by“▼”The “▲”Press the key to decrease or increase the output voltage of the instrument. Every press“▼”The key can lower the output voltage by one gear until the first gear is reached; Every press“▲”The key can increase the output voltage by one gear until high gear (7th gear), and at the same time, the instrument has an indicator light indicating the output matching gear at any time.

Explanation: Due to the automatic alarm and protection functions of the instrument, users do not have to worry about output overload damaging the instrument during the adjustment process.

④ continuous/Intermittent key: Pressing this key allows the instrument to alternate between outputting continuous audio signals or intermittent audio signals.

⑤ ammeter Display the output current.

⑥ output socket Connect the test lead of the instrument and output the audio signal to the cable under test.

four operating steps

1. Security check

Before starting the operation, it is necessary to first confirm that the tested cable has been powered off, and short-circuit each phase and ground of the cable to release residual electrical energy to protect personnel and instruments.

2. Wiring

（1) Path detection wiring

lInterphase connection method

Connect the two output test leads of the audio generator to the two phases of the cable under test, and use a pathfinder probe to detect them. As shown in the figureAs shown in 4-1.

Due to the shielding effect of the cable sheath on the electromagnetic field, when wired in this way, the signal received by the receiver is weak. However, in the case of minimal external interference, a significant decrease in sound quality can be heard in the valley mode. Therefore, when the external environment is good, it is advisable to use a phase to phase connection method.

lThe phase to ground connection method connects the two output test leads of the audio signal generator to one phase of the cable under test and between the lead sheath (lead sheath grounded), and uses a path detector probe for detection.As shown in the figureAs shown in 4-2.

This wiring method allows the receiver to receive strong signals, but it is not easy to hear significant changes in sound. When the cable is buried deep or there is significant external interference, and the sound is too weak when using phase to phase connection method, it is suitable to use phase to ground connection.

attentionUsing the above two wiring methods, when the cable is long and the signal is strong, the opposite end of the cable can be open or short circuited; When the cable is short or the signal is too weak, a short circuit can be made between the energized phases at the opposite end to reduce cable impedance and increase output power.

lIndirect connection (direct coupling) method

Short circuit the two output test leads of the audio generator and wrap them around the lead sheath of the cable under test, usually by winding5-7 laps. The coupling coil can be regarded as an inductor, generating induced electromotive force and induced current, and emitting electromagnetic waves to the surroundings through the cable, which can be detected using a path detector probe. As shown in Figure 4-3.

The direct coupling wiring method can perform path testing without power outage. This method can be used when testing the path of certain cables that do not allow power outages.

lIndirect connection (direct coupling) method

Short circuit the two output test leads of the audio generator and wrap them around the lead sheath of the cable under test, usually by winding5-7 laps. The coupling coil can be regarded as an inductor, generating induced electromotive force and induced current, and emitting electromagnetic waves to the surroundings through the cable, which can be detected using a path detector probe. As shown in Figure 4-3.

The direct coupling wiring method can perform path testing without power outage. This method can be used when testing the path of certain cables that do not allow power outages.

picture4-4 Cable Identification Phase Ground Connection Method

3. Continuous/Intermittent State Selection

During testing, different working states can be selected according to the actual situation in order to achieve good testing results.

When the electromagnetic noise in the surrounding environment is relatively high or the signal is weak, the intermittent mode has strong anti-interference ability.

According to experience, when the signal is relatively clear,The intermittent method is better for path detection, and the continuous method is better for low impedance fault location.

4. Power on

Connect the instrument power cord and AC220VThree core power sockets must be connected and have good grounding.

After checking that the test leads are connected correctly to the cable under test, turn on the power switch and the instrument will emit a signalDrip——”After the startup prompt sound, it is in standby mode. Users can adjust the output impedance of the instrument by operating the "Output Matching Adjustment" button according to the different load impedances, achieving the goal of matching the instrument with the load impedance and maximizing the output current. This can achieve better testing results.

The instrument can change its continuity at any time according to the actual situation during operation/Intermittent working state. When in continuous state, the instrument will emit a continuous "squeak -" sound; When in intermittent state, the instrument will make intermittent "squeak -" sounds with intervals of1Seconds (both the time of speaking and not speaking)1Seconds).

The instrument has automatic overcurrent protection and alarm function. Short circuiting the two output test leads in any state will not damage the instrument. Therefore, users are operatingWhen pressing the "output matching adjustment" button, there is no need to worry about excessive output current causing damage to the instrument.

5. Testing

The test requires the use of a cable fault locator, please refer to the user manual of the cable fault locator for specific operation methods.

6. Shut down

After the test is completed, turn off the power switch of the instrument and remove the wiring.

five Simple fault handling

1Phenomenon: The power indicator light does not light up after booting up.

solve: check220VDoes the power supply have electricity;

Check if the power cord is reliably connected to the transmitter;

Check if the fuse is burnt out. If the fuse is damaged, please replace it(1A)。

2、phenomenon Chassis overheating

solve: Shutdown for a period of time to cool down before restarting for use.

When the instrument malfunction cannot be easily resolved, users are not allowed to repair it themselves to avoid exacerbating the problem. Please contact our company in a timely manner and we will be dedicated to serving you.

six Precautions

lThis instrument must use a well grounded three core power socket.

lResidual electrical energy on the cable should be released before wiring.

lConnect the wires and check for errors before turning on the power switch of the instrument.

lAfter turning off the power switch of the instrument, remove the wiring.