Current and Voltage Accuracy in Two Setting Methods

When setting the output current or voltage from DC power supply, a higher accuracy can be achieved by panel setting or remote PC setting instead of ammeter adjustment. Below explains the accuracy difference between these two methods taking PMX35-1A and PMX18-5A as an example.

CC Accuracy

1. Panel Setting/Remote PC Setting Accuracy
When setting CC with the SET button and knob, CC setting accuracy regards as how an actual CC value differs from a true value.
E.g.) For PMX35-1A and PMX18-5A, the setting accuracy value is: ± (0.3% of setting + 0.1% of rating).
When setting 300mA from the panel, the following error is included: PMX35-1A: ± (0.3 x 0.003 + 1 x 0.001) = ± 0.0019 (A)
PMX18-5A: ± (0.3 x 0.003 + 5 x 0.001) = ± 0.0059 (A)
It means that PMX18-5A may cause a larger error with this setting method. If you need to pass 1A, a higher accuracy can be achieved through PMX35-1A.
The same applies to the remote PC setting.
2. Ammeter Adjustment Accuracy
When setting CC (300mA) by adjusting an ammeter, the ammeter accuracy regards as how an actual CC value differs from a true value.
E.g.) For PMX35-1A and PMX18-5A, the ammeter accuracy value is: ± (1% of reading + 5 digits);
When setting 300mA by adjusting the ammeter, the following error is included: PMX35-1A: ± (0.3 x 0.01+ 0.005) = ± 0.008 (A)
PMX18-5A: ± (0.3 x 0.01+ 0.005) = ± 0.008 (A)
It means that PMX35-1A andPMX18-5A obtain the same error results with ammeter adjustment.

Generally, the higher accuracy can be obtained by setting from panel or PC instead of adjusting
the ammeter.
Therefore, the current accuracy will be determined which method to be used.
Conclusion:
To improve the current accuracy;
1) Choose DC power supply whose rated current is close to your required value.
2) Set current from SET button or PC instead of ammeter adjustment.

CV Accuracy

1. Panel Setting/Remote PC Setting Accuracy
When setting CV with the SET button and knob, CV setting accuracy regards as how an actual CV value differs from a true value.
E.g.) For PMX35-1A and PMX18-5A, the setting accuracy value is: ± (0.2% of setting + 0.1% of rating).
When setting 5V from the panel, the following error is included: PMX35-1A: ± (5 x 0.002 + 35 x 0.001) = ± 0.045 (V)
PMX18-5A: ± (5 x 0.002 + 18 x 0.001) = ± 0.028 (V)
It means that PMX35-1A may cause a larger error with this setting method.
If you need to apply 5V, a higher accuracy can be achieved through PMX18-5A. The same applies to the remote PC setting.
2. Voltmeter Adjustment Accuracy
When setting CV (5V) by adjusting a voltmeter, the voltmeter accuracy regards as how an actual CV value differs from a true value.
E.g.) For PMX35-1A and PMX18-5A, the voltmeter accuracy value is: ± (0.5% of reading + 2 digits);
When setting 5V by adjusting the voltmeter, the following error is included: PMX35-1A: ± (5 x 0.005 + 0.04) = ± 0.065 (V)
PMX18-5A: ± (5 x 0.005 + 0.04) = ± 0.065 (V)
It means that PMX35-1A andPMX18-5A obtain the same error results with voltmeter adjustment.

Generally, the higher accuracy can be obtained by setting from panel or PC instead of adjusting
the voltmeter.
Therefore, the voltage accuracy will be determined which method to be used.
Conclusion:
To improve the voltage accuracy;
1) Choose DC power supply whose rated voltage is close to your required value.
2) Set voltage from SET button or PC instead of voltmeter adjustment.
Please be sure to verify each setting accuracy and meter accuracy before setting the output.

Products Mentioned In This Article:

PMX Series please see HERE

How to Enable Positive/Negative Output from DC Power Supply

DC power supply can provide dual (positive and negative) output by following the method described in Section 1 below.
1. How to Produce Positive/Negative Output
1. Connect Power Supply 1 to Power Supply 2 in series.
2. Connect COM terminal to GND terminal.
3. Set each voltage from Power Supply 1 and 2.

2. Dual Tracking Function
Generally, DC power supply can feature ‘master-slave series operation’ function. With this function, Power Supply 1 acts as the controller for Power Supply 2.
E.g.) If Power Supply 1 outputs 5V voltage, Power Supply 2 automatically outputs also 5V voltage.
In dual (positive/negative) output power supply, this function is called as ‘dual tracking’ function that varies positive and negative voltages simultaneously.
Some Kikusui’s DC power supplies support the master-slave series operation. For the function availability, please check the user’s manual of your model or see Table 1 in the next page.
In addition, if you output from two units of PCR-LE Series with 2P05-PCR-LE (optional board for single-phase three-wire output) in DC output mode, these units can act as dual tracking power supply.

3. Dual Tracking Function Availability

Products Mentioned In This Article:

To view all Kikusui Power Supplies please see HERE

PLZ Series: How to Effectively Improve Safety during Load Testing of Non-isolated AC/DC Converter

Considering minimising the potential shock hazard, the use of an isolation transformer or regulated power supply is critical during load testing of a non-isolated AC/DC converter (such as PFC). This white paper explains; what happens without an isolation transformer or regulated AC power supply and how important these are for safety reasons.
1. What happens if non-isolated AC/DC converter is directly connected to electronic load?
Figure 1: Since the DUT is non-isolated, the capacitor of electronic load, which placed at its DC input, passes the current though the enclosure of electronic load to the leakage breaker, thus shutting the breaker off.

Figure 2: Example that the GND terminal of electronic load (at the power plug) is not grounded; The leakage breaker will not shut itself off, but the voltage is applied to the enclosure of electronic load. Contacting such electronic load could expose an operator to an electric shock. Note: Our user’s manual advises users; ‘Be sure to earth ground the product to prevent electric shock’.

2. Preventive Action
To prevent the above interruption or shock hazard, add the isolation transformer or AC regulated power supply as shown in Figure 3, which can provide the electrical isolation between the utility power line and the primary and secondary terminals of DUT. This can greatly reduce the potential shock hazard for an operator.

3. Non-isolated DC/AC Converter Testing
The same situation may occur while performing a load testing on a non-isolated DC/AC converter (such as power conditioner) by using our AC electronic load PCZ1000A. In this case also, we highly recommend to use an isolation transformer or regulated power supply.

Products Mentioned In This Article:

To view all PLZ Series please see HERE

PBZ Series: How to Change Pulse Width Using Sequence Function

PBZ Series can change the square waveform frequency and duty cycle. Using the sequence function, you can also change the pulse width. The following sections explain how to change the pulse width according to Ton/Toff specified in figure 1 and table 1.

2. Create and Execute Sequence
1) Square wave frequency and duty cycle: See the ‘Setting’ column in Table 1. FREQ=1/ (Ton+Toff), DUTY=Ton/ (Ton+Toff)
2) Enter the above data into the sequence creation software (Wavy for PBZ).
Table 2 shows the sequence example of the first four steps.
Note: Enter 0 in the Phase field. Interval should be shorter than one time period of the square waveform.

Figure 2 shows the actual generated waveform (for Ton).

Products Mentioned In This Article:

PBZ Series please see HERE

How to Calculate Input Current for PCR-LE/MA Series

Before installing PCR-LE or MA Series, you may want to know how much current should be supplied from the distribution board. The best way is to calculate the current consumption (= input current) of your PCR-LE or MA Series. Here are the examples how to calculate the input current based on your output requirement (your output voltage and current):
Example 1: PCR3000LE
Condition: Input Voltage: Single-phase, 200 VAC
Output Voltage: 230 VAC rms, 10 A
Method 1: Calculate based on Input Current Characteristics Graph
See Figure 1 from User’s Manual of PCR-LE Series – ‘Operating Characteristics’ (Page 93).

1. Calculate output current ratio

The output voltage is 200 V or higher: e.g. 230 V as above example. Calculate the percentage of output power to the rated power. This percentage is regarded as output current ratio:
Output power: 230 V x 10 A = 2,300 VA
Output current ratio: 2,300 VA / 3,000 VA = 0.766 = 76.6% 2. Find input current
You can find the input current through the red points on the above graph: e.g. If output current ratio is 76.6%, the input current is approx. 21 A.

Method 2: Calculate based on Efficiency Characteristics Graph
See Figure 2 from User’s Manual of PCR-LE Series – ‘Operating Characteristics’ (Page 93).

1. Calculate output current ratio
The output voltage is 200 V or higher: e.g. 230 V as above example. Calculate the percentage of output power to the rated power. This percentage is regarded as output current ratio:
Output power: 230 V x 10 A = 2,300 VA
Output current ratio: 2,300 VA / 3,000 VA = 0.766 = 76.6%
2. Find efficiency
You can find the efficiency through the red points on the above graph: e.g. If output current ratio is 76.6%, the efficiency is approx. 57%.
3. Calculate input power (active power: W)

Input power (active power): 2,300 VA / 0.57 = 4,035 W
4. Calculate apparent power (VA) and input current

The power factor from the specification: 0.97
Input power (apparent power): 4,035 W / 0.97 = 4,159 VA Input current: 4,159 VA / 200 V = 20.79 A = approx. 21 A.

Example 2: PCR1000MA
Condition: Input Voltage: Single-phase, 200 VAC
Output Voltage: 200 VAC rms, 3 A
Method 1: Calculate based on Input Current Characteristics Graph
See Figure 3 from User’s Manual of PCR-MA Series – ‘Operating Characteristics’ (Page 63).

1. Calculate output current ratio

The output voltage is 200 V or higher: e.g. 200 V as above example. Calculate the percentage of output power to the rated power. This percentage is regarded as output current ratio:
Output power: 200 V x 3 A = 600 VA
Output current ratio: 600 VA / 1,000 VA = 0.6 = 60%

2. Find input current
You can find the input current through the red points on the above graph: e.g. If output current ratio is 60%, the input current is approx. 4.4 A.

Method 2: Calculate based on Efficiency Characteristics Graph
See Figure 4 from User’s Manual of PCR-MA Series – ‘Operating Characteristics’ (Page 63).

1. Calculate output current ratio
The output voltage is 200 V or higher: e.g. 200 V as above example. Calculate the percentage of output power to the rated power. This percentage is regarded as output current ratio:
Output power: 200 V x 3 A = 600 VA
Output current ratio: 600 VA / 1,000 VA = 0.6 = 60%
2. Find efficiency
You can find the efficiency through the red points on the above graph: e.g. If output current ratio is 60%, the efficiency is approx. 75%.
3. Calculate input power (active power: W)

Input power (active power): 600 VA / 0.75 = 800 W
4. Calculate apparent power (VA) and input current

The power factor from the specification: 0.9

Input power (apparent power): 800 W / 0.9 = 888 VA Input current: 888 VA / 200 V = 4.44 A = approx. 4.4 A.

Below is the Operating Characteristics Graph for PCR2000MA/4000MA as reference.
You can also calculate the input current for PCR2000MA/4000MA using the same method as above.

Products Mentioned In This Article:

• PCR-MA Series please see HERE
• PCR-LE Series please see HERE

Parallel Operation with Different Power Supply Models

The same model of Kikusui DC power supplies can be connected in parallel. By connecting the signal cables, one unit is set as the master unit and it can control the other units. This operation is called as ‘master-slave parallel operation’.
Master-slave parallel operation is not available when connecting the different power supply models. To increase the output capacity with the different models, the parallel operation described below is recommended. To perform this operation, you need to set the voltage or current for each unit. The simultaneous power on/off is available with the external control. Below is the operation example.
1. Parallel Operation in Constant Voltage (CV)

Firstly, connect two different power supplies ‘PS1’ and ‘PS2’ in parallel as shown in Fig. 1.
1. Set the output voltage for PS1 and PS2. The output voltage value for PS1 should be approx.
0.3V higher than that of PS2.
2. Set the rated CC value for PS1 and PS2.
3. Turn the output on for both units. The voltage is outputted from PS1.
4. Gradually decrease the load resistance to increase the current. Since the setting voltage for PS1 is higher, the current flows from PS1 only. When the current exceeds the rated CC value for PS1, the output voltage changes to the setting voltage for PS2. Then, the current also flows from PS2. In this example, the total current (I1+I2) is: rated CC value for PS1 + PS2 (see Fig. 2).
During this operation, the output voltage changes with the current; e.g.) It changes 0.3V in the above example. If the same voltage is set for PS1 and PS2 (the voltage difference is 0V), the current becomes unstable that alternately flows from PS1 or PS2. The required voltage difference depends on the power supply type in use. Please set the appropriate voltage difference to keep the parallel operation stable.
2. Parallel Operation in Constant Current (CC)
To operate in CC mode, it is not necessary to set a specific voltage difference on each power supply. The constant current can flow from both PS1 and PS2.

Products Mentioned in this Application note:

Kikusui DC Power Supplies please see HERE

CC-CV Charging System without Series Diode
To charge batteries, it is recommended that you connect a diode in series at an output of DC power supply (See Figure 1). With a diode, constant current (CC) can be properly supplied; however constant voltage (CV) may be unstable if using remote sensing at battery terminals. Without a diode, a high current can flow between a battery and power supply when connecting or disconnecting a battery. Now, let me tell you other stable CC-CV charging methods with a switch instead of a diode.

1. Connect Sense Leads to Battery
1.1 System Structure
Connect a double switch (SW1) as shown in Figure 2; one is for the output on/off switch and the other is for the sensing (+S) on/off switch.

1.2 How to Set Voltage and Turn SW1 On
Set the output voltage equal to the battery voltage and then turn SW1 on.
Figure 3 shows the output voltage, output current and voltage at both terminals (A/B) of SW1 when SW1 is turned on.

First, the output voltage increases by approx. 0.6 V because the sensing switch (+S) is open. At the time when SW1 is turned on, the small overcurrent is generated because an output current starts flowing or a switch chattering occurs. After SW1 is turned on, the output voltage becomes nearly equal to the battery voltage; the current will stop flowing.
Finally, apply CV voltage to start CC-CV charging.
Note: If you initially set CV voltage and then turn SW1 on, an excess overcurrent flows as shown in Figure 4.

2. Connect Sense Leads to Switch
Figure 5 shows how to connect sense leads to switch (SW2). Set the output voltage equal to the battery voltage and turn SW2 on; an overcurrent will not flow.
Then, apply CV voltage to start CC-CV charging.

3. Others
Above systems can serve as your reference. Before configuring your own system, please be sure what type of switch you need.

Introduction

The SIGLENT SSA3000X, SSA3000X Plus and SVA1000X products are based on a similar swept superheterodyne spectrum analyser platform and have very similar starting prices. There are quite a few similarities, but also a few differences that could affect the end results for particular applications.

The table below compares the major specifications and the comparable options as they pertain to specific applications like VSWR.

*Compatible with many commercially available return loss bridges/directional couplers

Additional SVA Features and Options

Still having trouble choosing?

Here are some additional features and options that are exclusive to the SSA PLUS and SVA platforms that may help:

Free Features:

• Touch screen control with shortcut widget
• Mouse/Keyboard support
• Easy web browser web control
• Power-On-Line – Instrument will automatically restart when power is restored to the mains power connection (power cord) when this feature is enabled.

Additional Options:

• AM/FM modulation analysis (SVA1000X-AMA. SSA3000XP-AMA) enables visualization of data encoded using AM/FM
• Digital modulation analysis (SVA1000X-DMA. SSA3000XP-DMA) enables visualization of data encoded using FSK/ASK
• Advanced measurement kit (SVA1000X-AMK, SSA3000XP-AMK) feature Harmonic and CNR measurements in addition to CHP/ACPR/TOI/OBW/Monitor.
• Mechanical calibration kit for VNA (F503ME)

If you have additional questions, you can always contact our applications team (info@siglent.com) and we would be happy to answer any additional questions you may have.

Products Mentioned In This Article:

• SSA3000X Series please see HERE
• SSA3000X Plus Series please see HERE
• SVA1000X Series please see HERE

Here is a brief code example written in Python 3.4 that uses a socket to pull a display image (screenshot) from a SIGLENT SSA/SVA analyser via LAN
and save it to the local drive of the controlling computer.

NOTE: This program saves the picture/display image file in the same directory that the .py file is being run from. It will overwrite any existing file that has the same name.

Download Python 3.4, connect an analyser to the LAN using an Ethernet cable, get the scope IP address, and run the attached .PY program to save an image of the analyser display. The type of file saved is determined by the instruments setting when the program is run.

You can download the .PY file here: [Download not found]

Tested with:

Python 3.4
SSA3000X
SSA3000X Plus
SVA1000X

Many broadcast applications require monitoring a transmitter and observing the output amplitude vs. frequency. For FM radio applications, a common mask is defined by the National Radio Systems Committee (NRSC) and is commonly referred to as the FM NRSC mask.

A very helpful SIGLENT owner, Dan from Alabama Broadcast Services, LLC, built an FM NRSC Mask tool using our original AM NRSC mask python code (found below):
https://siglentna.com/application-note/build-nrsc-masks-siglent-ssa3000xs-using-python-script/

This program was built using Python 2.7 and helps create masks around user-defined centre frequencies.

Here is the URL to the zipped download of the finished Python code:
https://siglentna.com/wp-content/uploads/dlm_uploads/2020/02/SSA3XNRSC_FM_Limit.zip

The SIGLENT SSA3000X series of spectrum analysers have an on-screen peak detection that can be used to easily show the peak values in a

• Configure the instrument span, RBW, and amplitude to capture the signals of interest
• Send “:CALC:MARK:PEAK:TABL ON”
• Send “:CALC:PEAK:TABL? “ to return the peak table data

Here, we show the displayed peak table and the data return using a VISA interface:

Products Mentioned In This Article:

• SSA3000X Series please see HERE

From Wikipedia: Intrinsic safety (IS) is a protection technique for safe operation of electrical equipment in hazardous areas by limiting the energy, electrical and thermal, available for ignition.

The idea is to minimise the risk of fire or explosion by physically eliminating any potential source of ignition.

Many IS circuits utilise special fusing and elements that are designed to dissipate the available power below certain temperature thresholds. During a fault condition, no component within the design can exceed this temperature rating.

Testing the performance of this type of design is quite simple: Load the circuit to pull the maximum rated power and measure the temperature of all of the circuit elements (heat sinks, packaging, resistors, etc..).

In practice, you could use a power resistor network with proper heat sinking for the load but a more convenient solution is to use an electronic load like the SIGLENT SDL1000X series.

The SDL1000X is available in 200 and 300 W versions and features a Constant Power (CP) operation mode as well as Constant Resistance (CR), Constant Voltage (CV), as well as user-defined limits to ensure safe operation within the application test requirements.

• Connect the Device-Under-Test (DUT)
• Select Constant Power (CP) Mode
• Set the current (I_range) and voltage (V_range) ranges for the test
• Set the Power you wish the load to sink
• Activate the load input

After the specified time limit for your test (see your device/environment specifics for details), you can measure the components/design temperature using a thermal camera or direct temperature measurements using thermocouples and DMM like SIGLENTs SDM3000X series. In fact, the SDM3055-SC and SDM3065X-SC products feature the ability to monitor temperature on up-to-twelve thermocouples to provide multi-point temperature readings from different points on your design.

Be sure to check heatsinks and components that are expected to dissipate the most power, but also other peripheral components and traces that may carry unexpected loads during a fault.

NOTE: In this picture, we show an open power supply with no shielding or case. For more accurate measurement, we recommend leaving as much of the original design (shielding/case/metalwork) in place to get the most representative measurement possible.

Products Mentioned In This Article:

• SDL1000X Series please see HERE
• SDM3000X Series please see HERE