1 00:00:00,540 --> 00:00:08,310 Measuring voltage voltage type there is two types of voltage which is DC and AC and we did mention the 2 00:00:08,370 --> 00:00:15,300 difference between them earlier when measuring voltage at the meter blobs are placed across the voltage 3 00:00:15,300 --> 00:00:23,910 source the Volt or meter are used to separate functions and ranges to measure DC and AC because AC is 4 00:00:23,910 --> 00:00:29,640 constantly changing with form measuring AC voltage is not a simple matter. 5 00:00:29,640 --> 00:00:37,670 This Volt on meet our emissions base with automatic voltage and we must mention that when measuring 6 00:00:37,670 --> 00:00:44,330 voltage the Volt on meter is used to by the voltage across the source which is different than when measuring 7 00:00:44,330 --> 00:00:50,790 current with the current in the circuit must flow through the Volt or meter to be measured. 8 00:00:50,990 --> 00:00:58,250 This make it far easier to measure voltage and circuit because the operator can simply place the probes 9 00:00:58,280 --> 00:01:05,510 across the component as it is while in the circuit while measuring current that both brutal the operator 10 00:01:05,510 --> 00:01:14,620 must physically interrupt the circuit unsold of and connect and insert the Volt o meter into the circuit. 11 00:01:14,630 --> 00:01:21,470 So you might have to unseal that component of that its connection so that you can measure the current 12 00:01:21,470 --> 00:01:23,720 flowing through it burnt. 13 00:01:23,790 --> 00:01:31,730 We must point out that the two voltage measurement ranges one for DC and other for the C and we will 14 00:01:31,730 --> 00:01:34,530 see how to measure both of these. 15 00:01:34,550 --> 00:01:41,400 Now let's look at this digital multimeter or Volt or meter. 16 00:01:41,610 --> 00:01:45,740 Uh we must skin set to host predictable. 17 00:01:45,740 --> 00:01:57,300 If we are measuring resistance and we doesn't know or we don't know how much that resistance is we must. 18 00:01:57,300 --> 00:02:00,460 But the scale of the highest value. 19 00:02:00,980 --> 00:02:11,630 Now we the props must be inserted into the sharks as you can see here and we must know the voltage polarity. 20 00:02:11,630 --> 00:02:14,980 As you can see in these two batteries this side is the positive. 21 00:02:14,990 --> 00:02:17,690 And this battery this side is the positive. 22 00:02:18,080 --> 00:02:25,700 So we must bless the positive Rob here and the negative probe here to better measure the voltage. 23 00:02:25,700 --> 00:02:29,860 Now let's look at how we can measure that battery voltage. 24 00:02:29,980 --> 00:02:34,730 Set up the Volt or meter on six hundred volt DC. 25 00:02:34,730 --> 00:02:40,910 As you can see here we are pointing at six hundred volt DC since this is a DC battery. 26 00:02:40,910 --> 00:02:47,930 Uh we much or almost touch red blob two plus as in here as you can see this is the red blob. 27 00:02:48,560 --> 00:02:56,660 And touch a black blob too negative as you can see here then we must read the voltage to the nearest 28 00:02:56,660 --> 00:02:57,590 1 volt. 29 00:02:57,680 --> 00:03:02,310 As you can see here this is a nine volt battery so it's displaying nine. 30 00:03:02,820 --> 00:03:06,130 And uh you can try this at home. 31 00:03:06,140 --> 00:03:08,440 I'm sure that you have wanted me to run the battery. 32 00:03:09,050 --> 00:03:15,930 Uh this is a very simple technique and we must be sure of what we choose. 33 00:03:16,340 --> 00:03:25,700 Uh I'm measuring a DC current here so I choose volt DC for measuring ac I must choose volt AC so you 34 00:03:25,700 --> 00:03:31,370 must take very good care of this setup before I start measuring anything. 35 00:03:32,390 --> 00:03:35,710 And now let's touch the blob. 36 00:03:35,720 --> 00:03:41,820 The negative battery that the blob as you can see here we are reversing the connection and we touch 37 00:03:41,840 --> 00:03:44,930 the black blob to the positive side. 38 00:03:44,930 --> 00:03:46,930 We are reversing the connection. 39 00:03:47,130 --> 00:03:50,730 Uh and we read the voltage to the nearest 1 volt. 40 00:03:50,930 --> 00:03:56,810 As you can see there is a minus sign here which shows the world is negative. 41 00:03:56,810 --> 00:04:04,460 Since we are measuring it in the reverse manner the purpose of this exercise is to show that the Volt 42 00:04:04,490 --> 00:04:08,830 o meter can tell the difference between negative and positive voltages. 43 00:04:09,200 --> 00:04:16,580 We must point out that some Volt or meter particular another type will not be as forgiving that putting 44 00:04:17,000 --> 00:04:20,030 the probes on reverse voltage can damage the meter. 45 00:04:20,030 --> 00:04:29,060 So if you have an analog Volt or meter you shouldn't try this uh just place the positive on the positive 46 00:04:29,060 --> 00:04:33,540 side on the negative on the negative side. 47 00:04:33,560 --> 00:04:45,140 Now let's see if we are to out another to take another example using a vulgar scale that is closer to 48 00:04:45,140 --> 00:04:48,500 the actual voltage shown an improvement in the resolution. 49 00:04:48,560 --> 00:04:55,490 So if we know that this is an eye involved better while choosing a 600 volt scale or if we are or we 50 00:04:55,490 --> 00:05:00,830 know that this battery will measure a Volt between 1 and 20 why choosing 600. 51 00:05:01,100 --> 00:05:04,270 This will decrease the resolution significantly. 52 00:05:04,490 --> 00:05:10,910 Uh in this case we know that this is a 9 volt battery so we are adjusting the scale now set up the rule 53 00:05:10,920 --> 00:05:16,020 involved o meter on 200 volt DC skid touch red blob. 54 00:05:16,030 --> 00:05:19,310 The positive and touch black properties are the negative. 55 00:05:19,940 --> 00:05:23,260 Let's read the voltage to the nearest point to unfold. 56 00:05:23,270 --> 00:05:27,270 Not one volt as you can see in nine point five volt. 57 00:05:27,320 --> 00:05:32,560 Which means that we have a way a much higher resolution. 58 00:05:32,600 --> 00:05:34,440 Uh this is very silly. 59 00:05:34,450 --> 00:05:35,840 There is a zero here. 60 00:05:35,900 --> 00:05:44,630 Now we if we did another adjustment and blazed the Volt o meter and the 200 volt DC scale as you can 61 00:05:44,630 --> 00:05:45,680 see here. 62 00:05:46,280 --> 00:05:53,740 Now let's touch the red blob to the positive and the black blob that are negative and read the voltage 63 00:05:53,790 --> 00:06:03,140 the nearest Born 0 1 volt as you can see here nine point five and the zero claim here unlike the previous 64 00:06:03,140 --> 00:06:03,880 example. 65 00:06:03,920 --> 00:06:06,700 As you can see the Zero was here. 66 00:06:06,980 --> 00:06:07,960 Now it's here. 67 00:06:08,030 --> 00:06:12,210 So we have our much higher resolution. 68 00:06:12,290 --> 00:06:21,200 This is a very good example uh that you must at least have a clue how much the voltage should be or 69 00:06:21,200 --> 00:06:25,760 in what range so that you can get a good result. 70 00:06:25,760 --> 00:06:31,340 Now let's start let's look at this one point five volt battery example. 71 00:06:31,490 --> 00:06:36,200 Set up the Volt or meet up to 20 volt DC touch. 72 00:06:36,200 --> 00:06:43,020 The red blob and the black robe and the positive and negative direction using our unborn 5 volt battery. 73 00:06:43,140 --> 00:06:46,390 Read the voltage thumbnails buoyant 01 volt. 74 00:06:46,400 --> 00:06:48,440 As you can see it's a three. 75 00:06:48,620 --> 00:06:51,580 Breathing is one point five two. 76 00:06:52,090 --> 00:07:03,850 The tool here means that we have a very very high resolution and that we can measure in military volt 77 00:07:03,860 --> 00:07:06,840 range not just the Volt range. 78 00:07:06,860 --> 00:07:16,730 Now let's see the next example in which we will look at the battery but in the middle of volt scale. 79 00:07:16,730 --> 00:07:25,760 Now let's set the Volt on Meet of the 2 200 million volts skin the scale reading two hundred two thousand 80 00:07:25,820 --> 00:07:28,130 Miller Volt or two volts. 81 00:07:28,130 --> 00:07:31,750 Does that add up to the positive and the black blob. 82 00:07:31,750 --> 00:07:32,210 There we go. 83 00:07:32,490 --> 00:07:33,890 OK. 84 00:07:34,020 --> 00:07:37,130 Now we are using the 2000 scare. 85 00:07:37,940 --> 00:07:43,580 Well actually using the two volt scared because two thousand million volts is the same as two volts 86 00:07:44,000 --> 00:07:46,200 but because that simply is in level. 87 00:07:46,220 --> 00:07:53,270 That is not the small point in this case a rating of one thousand five hundred twenty seven million 88 00:07:53,270 --> 00:07:57,110 volt is the same as one point five to seven Volt. 89 00:07:58,160 --> 00:08:06,680 So as you can see here we are using them in the Volt range and we are sitting here and Volt o meter 90 00:08:06,830 --> 00:08:08,510 as you can see now. 91 00:08:08,750 --> 00:08:17,270 And this one point five volt battery we carry the voltage Tony Harris volt 0 0 1 volt and the rating 92 00:08:17,270 --> 00:08:27,440 is given as 1500 to 27 volt it's equal to one point five to seven Volt. 93 00:08:27,890 --> 00:08:29,420 So as the same. 94 00:08:29,630 --> 00:08:33,910 But you just make the resolution however much higher. 95 00:08:34,940 --> 00:08:45,230 Now to see if we want to look at the other example in this example we are setting our volt meter on 96 00:08:45,230 --> 00:08:52,580 2000 level this is scale and we are touching the red blob with the positive and the negative Rob with 97 00:08:52,580 --> 00:08:54,040 the negative side. 98 00:08:54,040 --> 00:09:02,530 We are using a nine volt battery and this is clearly an over voltage situation not reading it Swan. 99 00:09:02,690 --> 00:09:10,120 So you must know what happens if you use a scale that is too low for the voltage being major. 100 00:09:10,310 --> 00:09:16,190 As long as you do not exceed the maximum voltage value of the meter in this case six hundred volt there 101 00:09:16,190 --> 00:09:18,060 will be no physical damage to the meter. 102 00:09:18,560 --> 00:09:24,800 Let me tell indicates an over voltage situation by displaying a single digit one of the far left. 103 00:09:24,800 --> 00:09:33,800 This over a overage indication is consistent with the over all the other functions to be looked at later. 104 00:09:34,070 --> 00:09:41,380 So one means that we have over voltage and we didn't choose the right resolution. 105 00:09:41,390 --> 00:09:49,550 Now let's talk about safety and measuring uh when measuring voltage the voltage being measured execs 106 00:09:49,610 --> 00:09:58,200 is exposed to the operator and flowing through the props by cautions B alternative or be attentive. 107 00:09:58,550 --> 00:10:00,600 Watch what you watch what you touch. 108 00:10:00,620 --> 00:10:03,320 We shouldn't touch the props while measuring voltage. 109 00:10:03,570 --> 00:10:08,090 The blobs have sharp buoyant so that you can make precious contact. 110 00:10:08,100 --> 00:10:14,340 Use the protective shields when probes not in use so that they won't harm anyone. 111 00:10:14,350 --> 00:10:22,860 Observe the meter maximum limits for voltage and current fuels are a last resort protection feature. 112 00:10:22,940 --> 00:10:27,510 If you blow a fuse you made a mistake a very big one actually. 113 00:10:27,680 --> 00:10:36,830 So you must spend some time in safety so that you won't get harm or you won't harm anyone around you. 114 00:10:38,960 --> 00:10:45,560 The operators of the Volt meter could be exposed to lethal voltage and current levels also in probing 115 00:10:45,710 --> 00:10:53,150 alive circuit careless cross contact and the resulting short circuits could draw out equipment damaging 116 00:10:53,150 --> 00:10:56,620 levels of voltage and current the circuit under test. 117 00:10:56,780 --> 00:11:04,340 So you might harm the circuit damage components while measuring all while using digital multimeter or 118 00:11:04,340 --> 00:11:10,680 Volt or meter uh you must practice before going to circuits. 119 00:11:10,690 --> 00:11:16,220 You must practice with the components you must practice with damaged circuits then go to the real life 120 00:11:16,220 --> 00:11:19,480 circuits and real life problems. 121 00:11:19,550 --> 00:11:27,460 A good technique is the do a dry run of broad placement with mouth turned off during the dry run. 122 00:11:27,500 --> 00:11:34,970 The operator can see if the probe placement is correct and not short circuiting to damaging voltage 123 00:11:35,210 --> 00:11:37,170 and current breaths. 124 00:11:37,190 --> 00:11:43,430 Probably Osment and once confidence turn on the ball source to make the measurement another good technique 125 00:11:43,520 --> 00:11:49,190 is to sort all measurement of the high scaling level and then adjust the scale down downward to the 126 00:11:49,190 --> 00:11:50,720 appropriate living. 127 00:11:50,750 --> 00:11:58,020 There are usually automatic protection features involved or meters but it is the best or it is best 128 00:11:58,020 --> 00:12:04,500 not to consistently depend on them doing their intended jobs. 129 00:12:04,560 --> 00:12:08,460 That's it for measuring voltage and for safety and measuring voltage. 130 00:12:08,520 --> 00:12:17,460 I know that this lesson was really long but I'm sure that you learned a lot of things in one lecture 131 00:12:18,480 --> 00:12:25,770 and we kept it connected since this all experience are related to each other. 132 00:12:25,770 --> 00:12:26,970 Thanks for watching. 133 00:12:26,970 --> 00:12:29,370 See you next in measuring color.