Page 227 - Troubleshooting Analog Circuits

214 Index

passive components, 26-49 eyelets, 55,56, 170 mercury-wetted, 61
patents, xi, 78 foil peeling or lifting, 50-51 reed relays, 61
PC Boards. See printed-circuit boards hairline opens, 5 1 small-signal, 62
Pease’s Principle, 99,112, 137, 175, hairline shorts, 51 solid-state, 61-62
178 lack of guarding, 54-55 problems with relays:
phase detector. See under digital ICs leakage, 50.52-55, 128, 156, 177 coil lacks clamp diode, 36-37
phase shift, 89,93,99, 101-102, 106, long tails/dielectric absorption, 5 1 contact bounce, 61
11 1,116,128,143,151 need for high-quality, power, and contacts burning, 61
picoammeter. See under current meter digital grounds, 57, 129-130 “dry failures,” 61
Philbrick. See Teledyne Philbrick need for Kelvin connections, need for R-C network, 61
philosophy, 1-12.99. 118, 169, 171 57-58,59 leakage, 61
Photo-couplers. See Opto-isolators mislocation of components, 8.55 mercury freezes at -38 “C, 61
plans, logical, 5-12, 151, 175 moisture, 50.55 package leakage (at warm
pliers, 9,23 plated-through holes, 50,55-56 temperatures), 61
Popsicle stick with capacitors, 1-165 probe points, 55 position sensitivity (mercury-
potentiometers. See resistors, adjustable ringing, 44-45,44,56, 100 wetted), 61
potting, epoxy, 54 solder shorts, 50-51,176,180 small signals in high-power
power dissipation, 137, 178 “Spaghetti” syndrome, 56 type, 61-62
power supplies. 1-2, 17-18,18,20,22, stray capacitances too small thermocouples, 61
34,37,3941,57-58, (smaller than breadboard), rental (equipment), 14.83
89,106,110-111,118,124,139, 103 repair technician, 8,173
163. See also under voltage stray capacitances too big, 103, repairs, 2,8,54, 138, I73
regulators 144 resistors, adjustable, 30-32.19, 188
power supply reversal, 118,119, strip-line layout, 122 types of adjustable resistors:
163-164,163,164 too much “neatness,” 56 carbon, 30,32
anti-reversal rectifiers on each PC unsuitable board material, 50-5 I cermet, 30
board, 118-1 19, 163-164 washing (dish-washer), 54,170 conductive plastic, 30
anti-reversal rectifiers at each probes for ICs, 15,16,21 multi-turn, 30-3 1
power supply, 118-1 19, probes, oscilloscope, 14, 15,15,16,51, potentiometers, 30-32, 153, 177,
163-164 67,89, 106 188
“improve reliability by leaving out lx, 15, 100, 155 rheostats, 30-31
parts,” 118 Ix/lOx, 15, 106 trim-pots, 30,128, 153,174, 188
power-saving circuit with lox, 15,51,89,106,150,156,158 wire-wound, 30.32
MOSFET, 164.164 active, 15 problems of adjustable resistors:
series diodes, 163,163 current probes, 15.35, 160, 161 current, too much, 31-32
power transformers. See under trans- frequency compensation of lox, 15. “dry failure.” See wiper current,
formers 15,89,150,156.158 too little
preamplifier, seismic, x ground wires of probes, 15,16,150, power, too much, 30-31
printed-circuit boards (PC boards), 155 resolution, 30-3 1
50-59, I1 1-1 13 low-capacitance, 15,16,126 settability, 30-31
coupling capacitors, 56 probing, 6-7,40,60, 126,162, 168,206 wiper current, too little, 32
eyelets, 55-56, 170 problems with (anythingfirefer to wiper current, too much, 32
foil, 50-5 1,55-57 specific topic of interest resistors, fixed, 26-31, 121-122, 133,
ground plane, 5657.162 production test equipment, 21, 154, 156 136, 139
layout, 55-58 production testing, 1,42,93, 173 types of fixed resistors: 27
materials: 50-5 1,51 carbon composition, 27,28,30,
“Fish-plate.” See phenolic R-C Substitution box, 18.19 109, 121
FR-4 (fire-retardant), 51 home-made R-C substitution boxes, carbon film, 27.28
G- IO. See glass epoxy 18,19 “conceptual,” (computer model),
glass epoxy, 50-5 1,51 high values of C, 18,19 144-145,204,206,208
phenolic, 50-5 I, 51 small values of R, C, 18,19 diffused, 29.82.83
polyimide, 51 “Twiddle-box,” 18 high tempco. See temperature-
Teflon (TM), 51 VI2 Electronics, 18 compensating types
beams made with copper-clad Radio Shack, 34 low tempco, 28-29
material, 16 “record before trigger,” 15 metal film, 26.28.28
multi-layer boards, 55 recorder, strip-chart. See under strip- monolithic. See diffused
plated-through holes, 50-56 chart recorder networks. See thin-film networks
probe points,55 rectifiers. See under diodes “Nichrome,” 29
screened map of components, 55 rectifiers, anti-reversal. See under precision films (low tempco),
solder mask, 50-5 1 power supplies 27-28,155
problems with PC Boards rectifier circuit, precision, 181 RN55D or RN60D. 26-28
bad layout, 55-58 regulators, voltage. See voltage regula- “Sichrome,” 29-30
bypass capacitors, 44.44,45. See tors temp-compensating, 27.29.32
also under capacitors for relays. 6142 thick-film or cermet, 28
bypassing types of relays: thin-film networks, 24,28
compensation capacitors, 56 “dry-circuit.” See small-signal “type HS”. See wirewound, “high-
contamination, 50,52,54-55 relays speed“
crosstalk, 50,55-56 gold-plated contacts, 61 wire-wound, “high-speed type,
dirty grounds, 57 high-power, 61 28-29