10 tips for using your power best to shorten the t

2022-09-23
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10 tips for shortening the test time with your power supply

tip 1 stop waiting for DUT

most test programs spend most of their time waiting. Unless you are transferring large amounts of data, computers, i/o, and instruments are usually not the problem. Before upgrading your computer hardware or adopting faster instruments, you should carefully check the execution process of the program

the first level of improvement

starts from checking whether the test puts the DUT in the state required by the next test. For example, if the DUT needs to be shut down at the beginning of the test. Then it should be shut down after the last test. If the DUT needs to be preheated for a specific test, it should be placed at the back of the test process, and the system timer should ensure that the DUT has a long enough startup time. These methods can provide great speed improvement, although they are not always implemented (an elaborate test plan usually considers this level of optimization)

improvement of the second level

the next level of optimization should be based on the actual test requirements. Typical steps are:

· add the load to the DUT, set its programming state, wait for the DUT output to stabilize

· connect the measuring equipment with the relay, wait for the relay to pull in

· set the measuring instrument, wait for the setting to complete

· initialize the measurement, Wait for the measurement to be completed

· disconnect the relay

· cut off the power supply

· wait for the DUT to output, but most of them are low-end products, which are stable

usually every step includes waiting for the completion of the action. In addition, most DUTs require a period of stabilization after power on or load conditions change. By separating the programming and waiting phases, you can program an instrument while waiting to reschedule the test

· add the load to the DUT

· connect the measuring device with the relay

· set the measuring instrument

· wait for all the above actions to be completed

- relay pull in

- measuring instrument stability

- DUT output stability

· initial measurement

G) result comparison: multiple experimental characteristic curves can be superimposed, reproduced, and Enlarge · wait for the measurement to be completed

· disconnect the relay

· cut off the power supply

· wait for the DUT output to stabilize

overlap the waiting cycle to minimize the total delay. When the DUT is stabilized, the test program is busy programming relays and setting up measuring instruments

to achieve overlapping waiting, use public or global timers. Each routine setting the instrument or DUT should tell the global timer the duration of each action; To determine which action requires the longest wait. Then, when the measurement or other tests require the completion of the above command, call a simple wait function, and wait until the global timer expires before continuing

· add the load to the DUT

· connect the measuring equipment with the relay

· set the measuring instrument

· wait for the global timer

· initialize the measurement

· wait for the global timer

· disconnect the relay

· cut off the power supply

with this method, the test does not need to wait longer than the absolutely necessary time for the instrument setting, and also makes the programming simpler

prompt 2 use multiple power supplies and overlapping GPIB operations to shorten the test time

if the measurement speed is the basic requirement, you can consider using multiple single output power supplies instead of a multi-channel output power supply. With multiple power supplies, you can overlap GPIB operations to avoid delays caused by sequential command processing in multiple output power supplies. In a multi-channel output power supply, the commands sent to each output should be processed in turn, one output at a time. When multiple power supplies are used, while one power supply processes commands, the other power supply can accept commands, and so on

this technology shows its advantages when querying the power supply. For multi-channel output power supply, you must send the measurement command and retrieve the response of the output before querying the next output. Since the measurement must be carried out one by one, it takes two measurement cycles to complete such a query

OUTPUT Dev1; "VOUT1?"

ENTER Dev1; "Volt1

OUTPUT Dev1;" VOUT2? "

ENTER Dev1;" Volt2 housing endowment insurance is a thankless thing for insurance companies

for multiple instruments, you can first send commands to all power supplies to start measurement, and then get back the response. Since the measurements are overlapping, this query only needs one measurement cycle

OUTPUT Dev1; "MEAS:VOLT?"

OUTPUT Dev2; "MEAS:VOLT?"

ENTER Dev1; "Volt1

ENTER Dev2;" Volt2

when you use the visa software driver, viqueryf() is a convenient function to query. However, this function does not allow overlapping operations. For overlapping queries, the query is divided into several steps with viprintf() and viscanf(). For example:

viprintf (videv1, "meas:volt? n")

viPrintf(viDev2, "MEAS:VOLT?n");

viScanf(viDev1, "%lf", Volt1);

viScanf(viDev2, "%lf", Volt2);

although the time saved by individual settings or query operations may be quite limited, for complex repeated tests, the cumulative time savings may have a considerable impact on the total system throughput

tip 3 use the built-in measurement capabilities of power supplies and electronic loads

with the built-in measurement functions of many power supplies and electronic loads, you can reduce the time and complexity of automatic testing. For the power supply, you can use these capabilities to measure the output voltage and current of the power supply. For the load, you can measure the input voltage and current of the load

a good example is to test a DC-DC converter with four outputs. You need to measure the input voltage to the converter and all four outputs to comprehensively test the device. If you use a digital multimeter to measure voltage, you need to use a multiplexer to perform each measurement in turn (Figure 1). In addition to the complexity of the test device, your test program also needs to wait for the multiplexer to convert and stabilize each measurement

you can also test the converter with DC power supply and electronic load (Figure 2). They have been connected to the DUT, and there will be no switch delay, so the setting and testing will be much faster. Attention should be paid to the use of remote sensing here. Although this method does not require this, it can provide measurement and adjustment at the DUT end, not at the load or DC power supply, so it is a good idea

since you don't need a switch, you can also get the benefits of faster testing, higher reliability and simpler configuration

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