First, the power sequencer profile

Power sequencer, simply means that through the control circuit within the device, in accordance with established procedures in order to turn on or off the power output, and power supply voltage, load equipment, power management of the machine, you can accurately monitor the voltage, the size is getting smaller , From 1U to 3U standard rack, mainly 8,10,12,16 road and so on. Widely used in automatic control, television broadcasting systems, audio broadcasting, power facilities and other systems.
In the audio equipment, the correct shutdown procedure is to turn off the power amplifier first, and then turn off the front-end equipment such as the exciter, frequency divider, mixer and so on; In the first off the power amplifier in order to prevent off the front equipment noise impact, damage to the speaker and amplifier. By using the power sequencer and connecting to different switch sockets, the power can be activated from the pre-stage equipment to the post-stage equipment one by one. When the power supply is shut down, on the contrary, effective and unified management and control of various types of power-using equipment are avoided Man-made mistakes in operation, reduce the impact of switching power supply equipment on the power grid, to ensure stable power system.

Second, the power sequencer in the audio system applications

The first is to use or not? If in some fixed places, such as large-scale venues or performances, the entire system has professional staff, sound engineers or operators can use the sound equipment, there is no need to use the timing switch, after all, the more simple the system, the failure occurred The lower the rate. Even if the use of time-sequencer, its function is more powerful, such as cascade can be multi-level, CUP control, computerized management, stability and power capacity is relatively large. So in a sense, the timing switch is more suitable for beginners.
In most occasions, such as the unit's conference room, background music system, karaoke OK business establishments, middle and low Di, personal home entertainment systems, fixed installation of small and medium venues, rocking it and other audio systems, very few Professional sound engineer in the operation, and some such as dance car, mobile performance sound system, school public address system, but also part-time management of the use of equipment, the normative operation is not strong, you need to join the appropriate timing power management, so that users Better grasp.
Facts have proved that in some current engineering configuration, the timing power supply has almost become the standard equipment, how to choose a reasonable, correct application, timely maintenance and hidden dangers in advance, the audio technology practitioners face a new topic.

Third, understand the timing of the key parameters

1) Power input and output: input voltage, input maximum current, output voltage, maximum output current, the number of channels, socket type.
2) The front panel control interface: timing switch; channel status LED.
3) channel delay interval, usually a fixed ＆#118alue, 1 ~ 1.5 s.
4) Switching devices: the internal power on-off controller, usually formed by the relay.
5) Standby power switch: to prevent the sequencer controller failure to control, turn off the switch, all channels through.
6) Control Input: There are generally 1 IO control interface (TTL level), used to detect the output load is short circuit and so on.
7) Control Communication: RS232 control interface for cascading and management of timing devices, ie, system expansion, transmission of address codes and status information.
8) Other parameters: such as equipment weight, specifications, work environment requirements.
Some powerful timing device, but also with a voltmeter, air switch, power filter and other functions.

Fourth, the use of precautions

1) According to the requirements of the correct connection, pay attention to the switching sequence and power capacity, and the system connection one-to-one, it is best to do a good job in the power plug on the label, before each use of inspection, conditional can do a good backup of the sequencer.
2) After power amplifier and other high-power equipment, because of the current work, the connector needs regular inspection, especially in mobile performance applications, the vibration of the transport process will cause loose plug in the wet weather to see whether there is oxidation Phenomenon, to avoid poor contact or oxidation resistance increases, heat damage.
3) The main reference to the number of access devices, power amplifiers and other high-power devices to determine the maximum power consumption timer selection, jack type and access current are different access to the mixer, audio processor, peripherals, before and after Level amplifier, the number of ways to meet the needs of the actual work, but also to avoid waste of resources.
4) In cascade use and expansion of equipment in many cases, attention should be paid to the total current access, the best lighting and other power supply sub-gate control.

Fifth, the expansion of the sequence of functions and control methods

In addition to the basic function of the timing device, there are some special models also have extended functionality, here to purify the power sequencer (PROBASSCO VS-801) as an example

Timing power supply
Firstly, it has the function of eliminating the electromagnetic interference between the systems (especially the lighting system) and has a significant effect on improving the sound quality of the audio system. Followed by the MCU control, intelligent control and control of multiple ways: key lock, manual keys, infrared remote control three direct methods; emergency / external control with level control, infrared control signal input, the standard RS232 serial port (IN / OUT ) External interface control, and even through the PC control software, 1 and more machine programming system control; in the timing control, you can set any one of the normally open mode, set the order of work when any phase Adjacent two switches between the action time (the longest time limit), functionally similar to the programmable timer function to meet some special user application requirements.

Sixth, the timing device troubleshooting

Under normal circumstances, the timing device failure, it is likely that the internal switch contacts bad, damaged, boot after listening to the presence or absence of pull sound, with or without a multimeter to measure the output, emergency situations can be used straight. The other is a certain way the plug loose, poor contact.
Check the input power before work instructions, input power is normal, see the output channel indicator, the control panel is normal. Abnormal sound odor, found that the problem should be quickly cut off the power. Control and low-voltage control part of the fault is relatively rare, the phenomenon of normal power supply, there is no response to boot.