# Engineer’s Corner

### IDENTIFYING CURB MARKINGS OR GLYPHS

IDENTIFYING CURB MARKING OR GLYPHS The next time you are out walking on the street, have a look at the sidewalk curbs. You will notice some cryptic markings either painted on the curb or carved into the curb like a Glyph or sometimes markings the on

### BATTERY SIZE AND CHEMISTRY

Battery technology is constantly evolving to yield ever more powerful and compact energy sources. Here is some battery data that has been compiled to help you choose which battery you should use when designing a product that uses batteries. Use this data as a reference

### GRAY CODE WHAT IS IT, AND WHERE IS IT USED

GRAY CODE WHAT IS IT, AND WHERE IS IT USED BY: Don McClatchie           Gray Code is employed in many electronic devices that use rotary switches for position encoders. The Gray Code also called “reflected binary code” or (RBC) was named after Bell Labs researcher Frank Gray

### AIR CORE INDUCTOR WINDING THE EASY WAY.

Air Core Inductor Winding The Easy Way The following information for winding RF coils is accurate to within 1% for nearly all small air core coils, where: L = Self Inductance in micro-henrys. N = Total number of turns. r = Mean Radius in inches. l = Length of coil in inches. b =

### HOW TO BUILD AN AUDIO PAD

HOW TO BUILD AN AUDIO PAD Audio pads are used to attenuate an audio signal for the purpose of matching required levels between different pieces of equipment. Pads can be built unbalanced or balanced depending on the signal requirements. We will start with the basic unbalanced

### COPPER WIRE RESISTANCE CHART

COPPER WIRE RESISTANCE CHART A.W.G. FEET PER OHMS OHMS PER 1000 FEET GAGE at 77 Deg F at 149 Deg F at 77 Deg F at 149 Deg F 0 10000.00 8621.00 0.100 0.116 1 7936.00 6849.00 0.126 0.146 2 6289.00 5435.00 0.159 0.184 3 4975.00 4310.00 0.201 0.232 4 3953.00 3425.00 0.253 0.292 5 3135.00 2710.00 0.319 0.369 6 2481.00 2151.00 0.403 0.465 7 1968.00 1706.00 0.508 0.586 8 1560.00 1353.00 0.641 0.739 9 1238.00 1073.00 0.808 0.932 10 980.40 847.50 1.020 1.180 11 781.30 675.70 1.280 1.480 12 617.30 534.80 1.620 1.870 13 490.20 423.70 2.040 2.360 14 387.60 336.70 2.580 2.970 15 307.70 266.70 3.250 3.750 16 244.50 211.40 4.090 4.730 17 193.80 167.80 5.160 5.960 18 153.60 133.20 6.510 7.510 19 121.80 105.50 8.210 9.480 20 96.20 84.00 10.400 11.900 21 76.30 66.20 13.100 15.100 22 60.60 52.60 16.500 19.000 23 48.10 41.70 20.800 24.000 24 38.20 33.10 26.200 30.200 25 30.30 26.20 33.000 38.100 26 24.00 20.80 41.600 48.000 27 19.00 16.50 52.500 60.600 28 15.10 13.10 66.200 76.400 29 12.00 10.40 83.400 96.300 30 9.50 8.30 105.000 121.000 31 7.50 6.50 133.000 153.000 32 6.00 5.20 167.000 193.000 33 4.70 4.10 211.000 243.000 34 3.80 3.30 266.000 307.000 35 3.00 2.60 335.000 387.000 36 2.40 2.00 423.000 488.000 37 1.90 1.60 533.000 616.000 38 1.50 1.30 673.000 776.000 39 1.20 1.00 848.000 979.000 40 0.93 0.81 1070.000 1230.000   If you liked this, Click here and sign up for our free monthly newsletter with helpful tips and other articles that you will also like.

### PREFIXES FOR NUMBERS

PREFIXES for NUMBERS Electronics, Radio and all of the Science fields use numbers that are wildly large and small. For the sake of working with these large numbers our culture has developed Prefix's to keep the numbers small enough to be workable. These are the most

### LOGARITHMIC VOLTAGE RATIOS

LOGARITHMIC VOLTAGE RATIOS BY: FRANK McCLATCHIE   dB  RATIO   dB  RATIO   dB  RATIO   dB  RATIO 6 = 1.995263 5 = 1.778279 4 = 1.584932 3 = 1.412538 2 = 1.258925 1 = 1.122019 0 = 1.000000 -20 = 0.10000 -40 = 0.01000 -60 = 0.00100 -1 = 0.891250 -21 = 0.08913 -41 = 0.00891 -61 = 0.00089 -2 = 0.794330 -22 = 0.07943 -42 = 0.00794 -62 = 0.00079 -3 = 0.707490 -23 = 0.07075 -43 = 0.00707 -63 = 0.00071 -4 = 0.630960 -24 = 0.06310 -44 = 0.00631 -64 = 0.00063 -5 = 0.562340 -25 = 0.05623 -45 = 0.00562 -65 = 0.00056 -6 = 0.501190 -26 = 0.05012 -46 = 0.00501 -66 = 0.00050 -7 = 0.446680 -27 = 0.04467 -47 = 0.00447 -67 = 0.00045 -8 = 0.398110 -28 = 0.03981 -48 = 0.00398 -68 = 0.00040 -9 = 0.354800 -29 = 0.03548 -49 = 0.00355 -69 = 0.00035 -10 = 0.316230 -30 = 0.03162 -50 = 0.00316 -70 = 0.00032 -11 = 0.281840 -31 = 0.02818 -51 = 0.00282 -71 = 0.00028 -12 = 0.251190 -32 = 0.02512 -52 = 0.00251 -72 = 0.00025 -13 = 0.223870 -33 = 0.02239 -53 = 0.00224 -73 = 0.00022 -14 = 0.199550 -34 = 0.01996 -54 = 0.00200 -74 = 0.00020 -15 = 0.177830 -35 = 0.01778 -55 = 0.00178 -75 = 0.00018 -16 = 0.158490 -36 = 0.01585 -56 = 0.00158 -76 = 0.00016 -17 = 0.141250 -37 = 0.01413 -57 = 0.00141 -77 = 0.00014 -18 = 0.125890 -38 = 0.01259 -58 = 0.00126 -78 = 0.00013 -19 = 0.112200 -39 = 0.01122 -59 = 0.00112 -79 = 0.00011 -20 = 0.100000 -40 = 0.01000 -60 = 0.00100 -80 = 0.00010 MULTIPLY OR DIVIDE THESE NUMBERS BY ANY FACTOR THAT ZERO dB IS SUPPOSED TO REPRESENT If you liked this, Click here and sign up for our free monthly newsletter with helpful tips and other

### STANDARD RESISTOR VALUES

STANDARD RESISTOR VALUES MOVE THE DECIMAL POINT FOR ANY VALUE 1%, 5%, 10% AND 20% ARE LISTED.        1% INCREMENTS        . 5% 10% 20%                                                       10.0     10.2     10.5      10.7   10.0 10.0 10.0 11.0      11.3    11.5     11.8    11.0 12.1     12.4     12.7     13.0    12.0 12.0 13.3     13.7     14.0     14.3    13.0 14.7     15.0     15.4     15.8    15.0 15.0 15.0 16.2     16.5     16.9     17.4    16.0 17.8     18.2

### ASCII EXTENDED CONTROL CHARACTERS

ASCII control characters (character code 0-31) 0- 32 characters in the ASCII-table are control codes to control peripherals such as printers. Symbol DEC OCT HEX BIN HTML Number HTML Name Description NUL 0 0 0 00000000 &#000; Null char SOH 1 1 1 00000001 &#001; Start of Heading STX 2 2 2 00000010 &#002; Start of Text ETX 3 3 3 00000011 &#003; End of Text EOT 4 4 4 00000100 &#004; End of Transmission ENQ 5 5 5 00000101 &#005; Enquiry ACK 6 6 6 00000110 &#006; Acknowledgment BEL 7 7 7 00000111 &#007; Bell BS 8 10 8 00001000 &#008; Back Space HT 9 11 9 00001001 Horizontal Tab LF 10 12 0A 00001010 Line Feed VT 11 13 0B 00001011 &#011; Vertical Tab FF 12 14 0C 00001100 &#012; Form Feed CR 13 15 0D 00001101 Carriage Return SO 14 16 0E 00001110 &#014; Shift Out / X-On SI 15 17 0F 00001111 &#015; Shift In / X-Off DLE 16 20 10 00010000 &#016; Data Line Escape DC1 17 21 11 00010001 &#017; Device