My Electronic Lab Tools & Equipments


Written by Lim Siong Boon, last dated 06-Jul-08.

email:    contact->email_siongboon  





Kikusui variable DC power supply PAD 35-10L 0~35V 10A

Tektronix 2445A 150Mhz Oscilloscope

Tektronix 466 100Mhz Oscilloscope

Leader LAG-120B Audio Generator

Electrical Hand Drill

Soldering Iron, Singapore Network Ethernet WiFi RS232 RS485 USB I/O Controller


  My DC Variable Power

The most important equipment that is required for electronics project. If you are looking into buying some equipment for doing electronics stuff, this should be the first one you should invest in. A good power supply can help you detect problem circuit quickly.

Some good must have features in a power supply,

- able to support high current and wattage.

- current and voltage meter.

- current limiting function.

Of course there are more high tech advance features, but these are the 3 most important function that I cannot live without.

With a higher current/voltage or wattage rating, you can power up wider range electronics devices.

Type of Usage Voltage Range (V) Current Range (A)
small scale electronics circuit testing 3 - 15 1 - 2
small to medium size motor, or large scale electronics circuit testing 3 - 24 3 - 6
motor and halogen bulb 12 - 24 6 - 12


Before connecting any load to the power supply, it is a good practice to adjust the current limit to a range which you think the load consume. When connecting to any unknown load or load that you suspected may have problem, it is a must to set a current limit, to prevent over drawing of current from the power supply. If there are short circuits in the load, current limiting can prevent huge current from flowing through and therefore reducing the chance of burning the whole circuit down. With proper limit, a short circuit wire could be warm rather than burning with red hot fire. A lot of the problem can be detected by observing the amount of current being drawn.




Regulated DC Power Supply


Model: PAD 35-10L 0~35V 10A

Voltage range:

0Vdc - 35Vdc

Current range:

0A to 10A




<1> adjustable current limit

To limit the current up to a value. If the current drawn is greater than the value set. The power supply will seize further current supply, such that the current supplied will not exceed the limit. With some voltage adjusted, press current limit button <5>, and turn, <1> to the required current limit.

<2> adjustable voltage

Adjusting the open terminal voltage to the requirement. This also sets the voltage limit of the power supply.

<3> over current indicator (C.C)

LED lights up if current drawn is greater than the limit set.

<4> over voltage indicator (C.V)

LED lights up if voltage at the terminal is greater or equal than the voltage setting. With open terminal (not connecting any load/circuit), the C.V LED should be lighted up. When loaded, the C.V LED should be off.

<5> current/Voltage limit button

Press the button to see the current limit being set.

<6> OVP function (over voltage protection)

Adjust a limit to the voltage, such that if the system's voltage exceed the setting, the own power supply equipment will be shut down, and OVP LED will be lighted up. A reset (Off/On) will be required to reset the power supply to normal working conditions. This is a safety feature in case the voltage at the terminal is greater than expected unintentionally.

<7> voltage meter zeroing

see voltage calibration

<8> current meter zeroing

see current calibration

<9> V.FS (voltage full scale)

see voltage calibration

<10> A.FS (current full scale)

see current calibration

<11> V.OS (voltage offSet)

see voltage calibration

<12> I.OS (current offset)

see current calibration

<13> Voltage display

see voltage calibration

<14> Current display

see current calibration






Setting up the power supply for use:

1) Always turn current/voltage knob to minimum (anti-clockwise) before switching on the power supply.

2) Switch ON the power supply.

3) Adjust the voltage knob to the voltage required. It is important to verify the voltage using a multi-meter. Do not rely solely on the voltage reading on the power supply equipment.

4) Press the current limit button <5>, and turn the current limit knob to the maximum current allowed. Always keep the current limit as low as possible to prevent over driving faulty circuit, which may result in burning/fire.

5) Switch OFF the power supply.

6) Connect up your circuits.

7) Switch ON the power supply.

8) If the voltage and current when switched on is not of expected, switched off the equipment and think over what is happening.



Calibrating the voltage display <13>:

1) Make sure the power supply is switch OFF.

2) Adjust the OVP <6> to maximum, to prevent the protection mode from activating.

3) Adjust the voltage knob to minimum (anti-clockwise).

4) Switch ON the power supply..

5) Insert a digital VOLTAGE-meter and it should read 0V across the +ve -ve terminal.

6) If it does not read zero volt, adjust V.OS <11> until the digital multi-meter reads 0V. adjustment should be small and slow as the reading needs about a minute to be stable.

7) After the digital multi-meter reads 0V, it means that the output voltage at 0V has been tuned. Check the power supply voltage display 0V too. If the display does not show 0V, adjust the voltage meter zeroing <7> to 0V reading on the power supply equipment.

8) Adjust to increase the voltage to exactly 30V shown on the multi-meter. The voltage display on the power supply may not shows the 30V. Adjust V.FS <9> to adjust the voltage display to show the 30V on the equipment. Note that adjusting V.FS do not change the voltage output from the power supply equipment.

9) The equipment should be calibrated. Adjust to varies voltage to check if the voltage display tally the reading shown on your multi-meter.


Calibrating the current reading <14>:

1) Make sure the power supply is switch OFF.

2) Adjust the voltage/current knob to minimum (anti-clockwise).

3) Insert a digital CURRENT-meter and it should read 0V across the +ve -ve terminal. Make sure the priority is correct or else your meter will be damaged. +ve probe connected to the +ve terminal, while the -ve probe to the negative. This forms a short circuit across the power supply terminal as a amp-meter is 0 ohm.

4) Switch ON the power supply. The C.C <3> indicator will light up to indicate over current. This is because the current limit knob is turn minimum, limiting the current.

5) Increase the current knob by a bit. This should turn off the C.C indicator.

6) Increase the voltage knob by a bit. The C.C indicator could be lighted up, with a current reading on the display <14>. The display reading should reads the same as your digital CURRENT-meter. Adjust to varies current limit to check if they are of the correct reading.

7) If the reading is incorrect, A.FS <10> and I.OS <12> will need to be adjusted as it is done for the voltage calibration. The procedure will be slightly more complicated as current measurement is not as direct as voltage measurement, however the priciple is still the same. Tuning the offset first followed by the meter zeroing, and lastly the full scale tuning.






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My Tektronix 2445A 150Mhz Oscilloscope

Volts measurement cursors Specification  
Time measurement cursors Form Factor Benchtop
Cursor tracking Bandwidth 150 Mhz
Alphnumeric Readouts Rise time 2.33 ns
Time Measurement Number of Channels 4 ch
Voltage Measurement Min. Vertical Sensitivity 2 mV/div
CRT Readouts Maximum Vertical Sensitivity 5 V/div
  Vertical(or Deflection Factor) Accuracy 2 %
  Input Coupling AC,DC,GND
  Input Impedance 1 MOhm
  Input Impedance (alternate) 50 Ohm
  Maximum Input Voltage 400 V(dc+p)
  Maximum Input#2 (for Impedance #2) 5 Vrms
  Main time base - lowest 10 ns/div
  Main time base - highest 1 s/div
  B Sweep Time Base (low) 10 ns/div
  B Sweep Time Base (high) 50 ms/div
  Time base Magnification factor (X?) x10
  Timebase accuracy 0.6 %
  Trigger Source External,Internal
  Trigger Modes AC,Auto,DC,HF-REJ,LF-REJ,Normal,Single
  Display Type Color CRT
  Display Size 12.7 cm
  User Interface Proprietary
  Out of Production


  CE Compliance Not on file
  UL Compliance Not compliant
  Power Requirements, Input Power Universal (Auto Sense and Switch)
  Physical Dimensions

Width: 330 mm

Height: 190 mm

Length: 434 mm

Weight: 9.3 kg(20.5 lb)

For more information regarding the use and operation of an oscilloscope, you can refer to the following document, the XYZ's of Oscilloscopes  from Tektronix.

XYZs of Oscilloscopes, Tektronix 03W_8605_2.pdf



My Tektronix 466 100Mhz Analog Storage Oscilloscope

scan version of the manual for tektronix 466 oscilloscope is available in *.pdf format., Singapore Network Ethernet WiFi RS232 RS485 USB I/O Controller



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