How to Read Resistance Scale in Analog Multi-Tester

March 9, 2017March 10, 2017 ~ Fix it Phillip ~ Leave a comment

Measuring resistance on electronic components whether doing it individually or in-circuit, is not simple unless you had learned how to read resistance scale using an ohmmeter of an analog multi-tester. It’s not as hard as you think maybe by looking the overwhelming numbers and values. Once you understand it, you will realize how simple it is.

As you can see in the image below, resistance scale is located in the top most part of a meter panel. You may have noticed a descending order of number. From left (∞) to right (0). In practice, reading values always starts from zero. Therefore we will read resistance values from right to left which is zero (0) to infinity (∞) .

Note: Reading resistance values is an exact opposite of reading “voltage” and “current” since ACV (Ac voltmeter) and DCV (Dc voltmeter) scale is in ascending order. You may have noticed how their values starts from left (0, 0, 0) to right (10, 50, 250).

Since we will read resistance values from right to left, see to it that the gaps between numbers are not equally divided. Please don’t get so confused why it is not equal. In fact, it’s not a big deal. After all what we need to learn is the value of each scale between each numbers. Those small vertical lines that divide on each number is a scale. Each scale has a value with respect to each nearest number.

To fully understand it, we will make a list of numbers from zero (0) to infinity (∞) with its individual scale and value.
See the red lines below the resistance scale and compare it to the list below.

0-1 – is divided by 5 scales. Each scale has a value of 0.2 ohm. Therefore 0.2 ohm multiplied by 5 scales is equal to 1 ohm.

1-2 – also divided by 5 scales. Each scale has a value of 0.2 ohm. Therefore 0.2 ohm multiplied by 5 scales is equal to 1 ohm. Adding all the value from zero, we get a total of 2 ohms.

2-5 – is divided by 6 scales. Each scale has a value of 0.5 ohm. Therefore 0.5 ohm multiplied by 6 scales is equal to 3 ohms. Adding all the value from zero, we get a total of 5 ohms.

5-10 – is divided by 10 scales. Each scale has a value of 0.5 ohm. Therefore 0.5 ohm multiplied by 10 scales is equal to 5 ohms. Adding all the value from zero, we get a total of 10 ohms.

10-20 – is divided by 10 scales. Each scale has a value of 1 ohm. Therefore 1 ohm multiplied by 10 scales is equal to 10 ohms. Adding all the value from zero, we get a total of 20 ohms.

20-30 – is divided by 5 scales. Each scale has a value of 2 ohms. Therefore 2 ohms multiplied by 5 scales is equal to 10 ohms.

Adding all the value from zero, we get a total of 30 ohms.

30-50 – is divided by 10 scales. Each scale has a value of 2 ohms. Therefore 2 ohms multiplied by 10 scales is equal to 20 ohms. Adding all the value from zero, we get a total of 50 ohms.

50-100 – is divided by 10 scales. Each scale has a value of 5 ohms. Therefore 5 ohms multiplied by 10 scales is equal to 50 ohms. Adding all the value from zero, we get a total of 100 ohms.

100-200 – is divided by 5 scales. Each scale has a value of 20 ohms. Therefore 20 ohms multiplied by 5 scales is equal to 100 ohms. Adding all the value from zero, we get a total of 200 ohms.

200-500 – is divided by 4 scales. Each scale has a value of 75 ohms. Therefore 75 ohms multiplied by 4 scales is equal to 300 ohms. Adding all the value from zero, we get a total of 500 ohms.

500-1k – is not divided by a scale. Therefore from 500, you will get the value of 1 kilo-ohms (1K) by adding 500 ohms. So, it is very obvious that the gap between 500 ohms and 1k is 500 ohms. Adding all the value from zero, we get a total of 1 kilo-ohms (1K).

1k-2k – is not divided by a scale. Therefore from 1K, you will get the value of 2k by adding 1K. So, the gap is obviously 1 kilo-ohms (1K). Adding all the value from zero, we get a total of 2 kilo-ohms (2K).

Note: K stands for Kilo which means Thousand.

Any value that goes beyond 2K or 2 kilo-ohms value has a very high resistance and exceed the x1 multiplier range of an ohmmeter.

Please note that the highest resistance scale is only limited to 2k or 2 kilo-ohm resistance. If you need to measure resistance which is higher than 2 kilo-ohms, set the ohmmeter range to a higher multiplier range and so on.

Learning to read resistance values is easy. Just by knowing the value of each scale individually could fulfill it. But there’s more to learn if you dig deeper.

Here are the questions that arises on your thoughts:

What is a multiplier?

These are the 4 range of an ohmmeter, as you can see in the image below. An ohmmeter is divided by four main settings.

a) x1 – select this range so that any value in the resistance scale is multiplied by 1.

b) x10 – select this range so that any value in the resistance scale is multiplied by 10.

c) x100 – select this range so that any value in the resistance scale is multiplied by 100.

d) x1k – select this range so that any value in the resistance scale is multiplied by 1k or 1 thousand.

Does each range is has its own sensitivity?

x1 – has the lowest sensitivity
x1k – has the highest sensitivity

What range should be used in resistance measurement?

x1 – Select this range if you are measuring resistance below 2 kilo-ohms.
x10 – Select this range if you are measuring resistance below 20 kilo-ohms.
x100 – Select this range if you are measuring resistance below 200 kilo-ohms.
x1k – Select this range if you are measuring resistance below 2 mega-ohms.

Learning resistance measurement is simple but you need to practice. Familiarize the value of each scale and memorize it. Put it in practice, measure the resistance of an actual electronic components such as resistors, transistors and diodes. It’s not very long you realize you’d already done it with ease.

If i missed something or messes something up, please put it in the comments below and i’ll gladly make an update right away.

How to Use an Analog Multi-Tester

March 5, 2017 ~ Fix it Phillip ~ Leave a comment

In this tutorial, you will learn the basics of using an analog multi-tester or multi-meter. We are using a SANWA-360TRF Model as our preference. If you already have a multi-tester different from this one, don’t worry any model is fine.

We will guide you into a simple way of learning on how to measure:

a) DC Voltage – A voltage in the battery (dry cell or wet cell) or from a rectified power supply. It is measured using a DCV (Dc voltmeter).

b) AC Voltage – A voltage in the mains-outlet (220 Vac) or from unrectified power supply. It is measured using an ACV (Ac voltmeter).

c) Resistance – Resistance of a resistor, semiconductor and a wire or coil of wire. It is measured using an Ω ( Ohmmeter).

d) Current – A small current flowing in the circuit. It is measured using DCA (Dc ammeter).

In this image you will see the corresponding names of its parts to get familiar with.

You may have noticed in this image (in the range selector area), It is subdivided primarily into four main sections.

1) ACV – is an AC voltmeter (enclosed with a red bracket) on upper-right side. It has 4 range of selections.

Here you can select:

a. 10 – Select this range if the voltage to be measured is less than 10 volts ac.

b. 50 – Select this range if the voltage to be measured is less than 5o volts ac but more than 10 volts ac.

c. 250 – Select this range if the voltage to be measured is less than 250 volts ac but more than 50 volts ac.

d. 750 – Select this range if the voltage to be measured is less than 750 volts ac but more than 250 volts ac.

2) DCV – is a DC voltmeter (enclosed with a white bracket) on upper-left side. It has 6 range of selections.

Here you can select:

a. 0.1 – Select this range if the voltage to be measure is less than 0.1 volts dc. You may have noticed how this range intersects with DCA (Dc ammeter section). Therefore it can be also used as a a dc ammeter but only within this range.

b. 0.25 – Select this range if the voltage to be measured is less than 0.25 volts dc but more than 0.1 volts dc.

c. 2.5 – Select this range if the voltage to be measured is less than 2.5 volts dc but more than 0.25 volts dc.

d. 10 – Select this range if the voltage to be measured is less than 10 volts dc but more than 2.5 volts dc.

e. 50 – Select this range if the voltage to be measured is less than 50 volts dc but more than 10 volts dc.

f. 250 – Select this range if the voltage to be measured is less than 250 volts dc but more than 50 volts dc.

g. 1000 – Select this range if the voltage to be measured is less than 1000 volts dc but more than 250 volts dc.

3) DCA – is a DC ammeter (enclosed with a white bracket) on lower-left side. It has 4 range of selections.

Here you can select:

a. 50μ – Select this range if the current to be measured is less than 50 microampere.

b. 2.5m – Select this range if the current to be measured is less than 2.5 milliampere but more than 50 microampere.

c. 25m – Select this range if the current to be measured is less than 25 milliampere but more than 2.5 milliampere.

d. 0.25 – Select this range if the current to be measured is less than 250 milliampere but more than 25 milliampere.

4) Ω – is an ohmmeter (enclosed with a white bracket) on lower-right side. It has 4 range of selections.

Here you can select:

a. x1 – Select this range if the resistance to be measured is very low, ranging from 0 ohms (short circuit) to 1kΩ.

b. x10 – Select this range if the resistance to be measured is ranging from 10Ω to 10kΩ.

c. x100 – Select this range if the resistance to be measured is ranging from 100Ω to 100kΩ.

d. x1k – Select this range if the resistance to be measured is ranging from 1kΩ to 1MΩ.

There are several practice that you need to know while making it as a habit when using a multi-tester.

1. Before using a multi-tester, make sure the pointer points to infinity position. It should look exactly like the image above.

By default, it should point exactly to infinity scale since it was properly set by the manufacturer. If not, slowly turn the “zero position adjuster” until it points exactly to infinity position.

2. Before using an ohmmeter (it doesn’t matter what range you have used), always short the test pins (red and black) to test if the pointer points to zero resistance. If not, turn the “zero ohm adjuster knob” until it points to zero.

3. Be careful in using an ohmmeter – make sure you are doing resistance measurement and not voltage measurement. Ohmmeter’s internal circuit is powered by a 3v battery. Accidental voltage measurement will amplify the current inside the circuit and can cause severe damage.

4. Before doing voltage measurement, be sure to identify whether it is an AC (alternating current) or DC (Direct Current) voltages.

5. Before doing voltage measurements, make sure you have selected the correct range so that the voltage to be measured is lower than the range being selected.

These are the basic information on how to use the multi-tester or multi-meter. On our next article, you will learn how to read the scale on voltage, current and resistance values. If you think i missed something or messes something up. Please let me know and i’ll gladly make an update right away.

Basic and Cheap Tools for Electronic Repairs and Assembly

March 3, 2017 ~ Fix it Phillip ~ Leave a comment

1. Multi-tester or Multi-meter – This is a measuring instrument that combines several functions into one unit. It can measure current, voltage, resistance. It is a must have measuring tool for every repair technician and electronic enthusiasts.

2. Soldering Iron – It is a tool used in soldering. There are many types of soldering iron available in the market. The most common is the “soldering pencil type”. In fact, it is most widely used for electronic assemblies and repairs.

3. Soldering Iron Stand – Of course you can work with a soldering iron without it’s stand. But speaking of safety, you’re not going to risk anything doing electronic projects and end up getting burned, are you?. Wherever the soldering iron go, there should be the stand also. I highly recommend doing that, otherwise you will know the consequences.

4. Desoldering Pump – Also known as “solder sucker”. This is a tool used to remove solder from a printed circuit board.

5. Screwdrivers – You can’t do repairs without this tool.

6. Side-cutter Pliers – Basically it is used for cutting wires or alternatively can be used for stripping wires.

With these tools you can start building your own electronic projects or start repairing defective electronic devices.

6 Electronic Components Every Beginners Should Know

March 2, 2017 ~ Fix it Phillip ~ Leave a comment

Please be informed that components listed below are those available locally and are most commonly used.

1. Resistors. There are many types of resistors. It can be classified on various types based on various factors. In asian countries, its rare to see all types of resistors except for: “Fixed Resistor” and “Variable Resistors” which is very common.

-Examples of a Fixed Resistor:

a. Carbon Composition Resistor