1971 , Volume , Issue Aug-1971
Contents
1. HEWLETT PACKARD JOURNAL AUGUST 1971 Copr 1949 1998 Hewlett Packard Co Lilliputian Measuring System Does Much Costs Little A mainframe costing less than 400 a choice of four functional snap on modules including a 500 MHz counter and an unusual battery pack are the elements of this rugged portable MOS LSI LED instrument system By lan T Band Hans J Jekat and Eric E May NOT VERY MANY YEARS AGO electronic counters were strictly laboratory instruments Nobody needed their kind of precision in frequency and time measurements anywhere else Today however what used to be labora tory precision is now commonplace in all kinds of equip ment and as a result electronic counters are in demand as general purpose service and maintenance tools One only has to look at the communications industry to see what s happened The crowded electromagnetic spectrum has been squeezed to make room for more and more channels To guarantee that each transmitter re mains within its allocated channel its frequency must be controlled to within a few parts per million Measuring frequency with this degree of accuracy requires an elec tronic counter Or look at the vast network of telephone cable and equipment over which millions of messages are transmitted daily To keep it in working order carrier frequencies must be measured and calibrated Tone bursts must be counted Millions of relays must be checked and timed These2. or mounted as a Y2 module in a com bining case mam Aluminum Case The cast aluminum case is a far better shield than most instrument cases By itself however it isn t a complete RFI shield Complete RFI shielding of the 5300A would require a metal screen behind the plastic tront panel of the mainframe Making Delayed Timing Measurements The front panel delay knob controls a time delay which begins at the instant the start channel is triggered Until the time delay has expired the stop channel cannot be triggered This allows the end point of the measure ment to be selected in much the same way as the delayed sweep on an oscilloscope allows a selected portion of a signal to be displayed The delayed time interval capability is particularly useful for relay timing measurements in which relay con tact bounce usually imposes a measurement problem see Fig 8 Instead of measuring the correct time during which the relay is closed most timer counters would measure only the duration of the first bounce terminat ing the measurement when the signal first passes through the trigger voltage selected for the stop channel With the 5304A however the contact bounce can be ignored by adjusting the delay to be longer than the bounce period Thus the true time interval until the contacts are opened again can be measured The bounce time can also be measured by increasing the delay slowly and measuring the time to each b
3. ACCURACY Synchronous with line frequency ZERO SET Left hand adjustable 1 full right hand optional ENVIRONMENTAL operating 0 to 55 C lt 95 RH 25 to 40 C WRITING MECHANISM Servo actuated Ink pen electric writing optional GRID WIDTH 10 in or 25 cm for 712A B S in or 12 em for 7143 8 PEN LIFT Manual electric optional POWER 7123A 115 230 V 10 60 Hz 30 VA 71298 115 230 V 10 50 Hz 30 VA 7143A 115 230 V 10 60 Hz 30 VA 71438 115 230 V 10 50 Hz 30 VA PRICE Option choice for both span and chart speed must be specified 7123A 60 Hz 750 00 71238 50 Hz 750 00 7143A 60 Hz 695 00 71438 50 Hz 695 00 OEM discounts avi Electronic Chart Integrator Option 035 0 2 of full scale count rate 20 C to 30 C 404 of full scale count rate 0 C to 55 C LINEARITY 0 2 of full scale count rate READABILITY 1 count RESPONSE TIME integration continuous zero time lag between main pen motion and Integrator pen respon BASELINE Front panel adjustable over entire chart width ENVIRONMENTAL Operating 0 C to 55 C 95 RH 25 C to 40 C FULL SCALE COUNT RATE 6 000 counts per minute standard ZERO DRIFT 12 counts per minute TYPE All electronic the Integrator records and formed between main pen s trace and baseline set point WRITING MECHANISM Servo actuated ink pen WRITING WIDTH Integral recorded on 1 inch grid r
4. Autoranging selects the gate time for maximum resolu tion without overtlowing the dis play A logarithmic output from the time base chip produces pulses at decade multiples of 1 us The counter counts until the fifth decade reaches a count of 9 then terminates the measure ment on the next logarithmic pulse Manually selected gate times are also available on up to 10 seconds Every stop pulse is precisely timed in relation to the same start pulse All these timing signals are generated at a single output terminal of the time base and are synchronized with the clock frequency so that propagation delay errors are cancelled Since all possible stop pulses are available on a single line it s a simple matter for the autoranging control circuits to select the first available stop pulse following the 90 000 count To position the decimal point and units correctly the mea surement range is determined by counting the number of stop pulses which occurred before the display was filled In the event that the frequency is too low to fill the display in a reasonable time an arbitrary limit of one second is set on the measurement time Longer gate times can be selected manually Let There Be Solid State Light The display of the 5300 system is another departure from the past A light emitting diode LED display was chosen as a step towards all solid state reliability Low voltage drive low power drain and an in plane wide viewing
5. angle display were other benefits of the LED approach Each digit of the display is formed by a 4 x 7 matrix of red light emitting gallium arsenide phosphide GaAsP diodes Fig 7 Characters of this type have more esthetic appeal than the simpler and more common seven segment type of display An added advantage of the dot matrix approach is redundancy if a failure oc curs in any one diode the character cannot be misinter preted as a different digit The 5300 display contains all six 4 x 7 arrays on a single ceramic substrate In keeping with the one digit at a time data transfer in the instrument the display is scanned rather than con tinuously lighted only half a digit being lit at any time 7 However the entire display is scanned 1 000 times every second so the display appears steady Since each diode can be on for only 1 12 of the total time its instantane ous bri htness must be 12 times higher than a static dis play This turns out to be an advantage with LED s since the gallium arsenide phosphide diodes have a higher effi ciency at high currents Thus although the peak current is high the average current and power required are less than would be needed for a static display of the same brightness The power saving is particularly important when the battery pack is being used Measuring Frequencies to 500 MHz Although the 5300A mainframe can count only to 10 MHz the snap on modules can great
6. are jobs for electronic counters The kind of counter that s needed for service and maintenance is quite different from the usual laboratory type It has to be simple rugged and reliable It has to be portable even battery powered since the equipment to be serviced is likely to be a communications link on a distant hilltop or the navigational equipment aboard a ship It has to be low enough in cost to be considered a general service tool And it has to have sufficient mea surement capability to fill the majority of service and test needs Mini System Hewlett Packard s answer to these requirements the 5300 Measuring System is equally at home on the lab bench or in a maintenance van Calling it a system may seem a bit pretentious since it s the smallest of HP s counters Yet its modular design gives it versatility and a repertoire of measurement capabilities that many full size instruments don t have including frequency mea surements to 500 MHz 100 nanosecond time interval resolution autoranging and battery operation The 5300 system is one of the first of the new breed of instruments that rely heavily on the newer technologies MOS large ation solid state light emitting diode displays high speed bipolar integrated circuits read only memo scale inte Cover You probably wouldn t find a 5300 Measur ing System among a moun 7x tain rescue team s standard equipment But one could be used at the base ca
7. in the display much faster than 10 times per second so the difference in the number of readings per second is undetectable and the longer measurement time allows the errors due to frequency modulation of the carrier to be averaged out A typical application of the 5303A would be calibra tion of a mobile transmitter at frequencies just below 500 MHz These transmitter frequencies must be maintained within an accuracy of 5 parts per million which would be about 2 5 kHz maximum error To measure the trans mitter frequency the 5300A 5303A can be placed a few yards away from the transmitting antenna with just a small vertical whip antenna connected to its BNC input terminal The 0 1 s range can be used for a rapid but coarse adjustment to 1 kHz A finer adjustment can be made by allowing the most significant digit of the dis play to overflow in a 1 or 10 second measurement giving a resolution of 100 Hz or 10 Hz Other measurement ranges allow resolutions down to 1 Hz for frequencies below 50 MHz which are prescaled by only 10 and 0 1 Hz below 10 MHz where frequencies are directly counted Making Precision Time Measurements As well as measuring a wide range of frequencies the 5300 system can measure time intervals between events or between different parts of a signal The 5302A snap on module can measure time with 100 ns resolution Its normal range is up to 1 000 seconds although it can be used to time events as long as 10 million s
8. is time multiplexed with the serial data and printed out in the correct position On all HP printers the decimal point is printed out as an asterisk Fig 9 Mea a true exponent for ex surement units are printed ample us is printed as 6 Pa S SX Fig 9 Serial to parallel converter at end of accessory cable converts BCD output of 5300A mainframe to par allel form required by many printers Fig 10 Battery pack fits between maintrame and snap on module It has handles and a detachable shoulder strap Portable Power Not only can the 5300 system go anywhere the user goes but it can take its own power too Model 5310A battery pack can power the s tem for up to eight hours l for calibrating mo ble where ause false counts or for awk ward spots such as the top of a high rack of equipment which is just a little too far away from the nearest power outlet for convenience without re This is essent bile equipment where extra power isn t ava ground loop currents may The battery pack Fig 10 is unusual in that it fits between the mainframe and the snap on module like the meat in a sandwich It thus becomes an integral part of the construction instead of an awkward appendage This also puts the large mass of the batteries in the middle so when the instrument is carried by the handles or the shoulder strap which are provided with the battery pack the package is well b
9. 8 Hewlett Packard Co Fig 5 What happens when a magnetic assembly is dis assembled then reassembled Operating point of alnico drops while the operating point of a ceramic magnet assembly is the same when reassembled remagnetizing is unnecessary linear B H demagnetization curve Magnetized pieces can be disassembled and reassembled without requiring remagnetization of the assembled motor Fig 5 Finally expensive materials such as cobalt and nickel are not used Electronic Integrator An easy way to record the areas under peaks of re corded curves is to record the integral of the main pen signal A second motor slider pen assembly can be in stalled on the Model 7123A B It shares the slider rod and magnetic circuit of the main pen assembly The main pen signal is integrated and recorded by the integrator pen on the grid at the right side of the chart paper Fig 6 The distance traversed by the integrator pen is related to the area under the main trace A movable front scale tab sets the baseline point Accuracy of the electronic integrator is 0 2 at 20 to 30 C Writing System The dynamic range of a capillary ink writing system ratio of fastest pen speed to the slowest depends upon pen tip geometry ink viscosity and ink pressure Writing systems with good high speed writing characteristics no skipping may have poor low speed characteristics such as ink bleeding Good writing characteristics over t
10. B Strip Chart Recorder has been de veloped specitically for dedicated applications The linear servo motor has only one moving part and has high reliability Copr 1949 1998 Hewlett Packard Co Fig 2 Construction of the Hewlett Packard linear motor The linear motor positions a wiper on a pi entiometer made of conductive epoxy film The ri ing position ignal is compared to an applied in gnal The dit ference voltage between these signals is amplitied and applied to drive the bobbin to reduce the error signa to a minimum 10 inch wide grid the Model 7143A B takes paper with 5 inch wide grid The entire radial field of the motor is produced by a permanent magnet Power consumption is lower than servo systems and there is almost no internal tempera Also tinuously with no noise or damage to the recorder Some ture rise the motor can be driven off scale con conventional systems need either complex off scale power reduction switches or expensive and noisy slip clutches to prevent overheating the motor 14 Linear Motor Design The linear motor Fig 2 has a radial permanent mag net field B that interacts with a tangential current I F reverses the force In this configuration the linear motor producing an axial force Reversing the current may be considered a large amplitude 10 inches low auss a frequency 2 Hz woofer With a field of 1000 5 coil o
11. NSITIVITY min 25 mV ims nine ws time sine wave to 10 MHz 190 mv pulse width 40 na Sensitivity can be decreased by 10 or 100 times using ATTENUATOR switch IMPEDANCE 1 MI ahunted by lesa than 30 pF TRIGGER LEVEL PRESET positon cemere wviggeting about 0 volta or continuously variable over the ange of 1 V to 1 V times attenuator setting SLOPE independent selection of triggering on positive or mive ope TIME INTERVAL RANGE 500 ne to 10 a RESOLUTION 100 ns to 10 ms in decade stops TIME INTERVAL HOLDOFF Front pane concenirie nob in sens variable dolay of approximately 300 un to 100 me between START Channel A and enabling of STOP Channel B may be disabled Electrical inputs during delay time are ignored PERIOD AVERAGE RANGE 10 Mz to 1 Mhz PERIODS AVERAGED 1 to 1 watomatically selected FREQUENCY COUNTED 10 MHE FREQUENCY RANGE 0 10 10 Mhz GATE TIMES Manually selected 61 1 10 seconds or AUTO OPEN CLOSE Totalizing RANGE 10 MHz max PRICE 300 00 HP Model 5310A Battery Pack 48 wattours nominal peration depending on lcally pon module hours rom minimum level indicated by LOW VOLTAGE INDICATOR Solld state warning light begins 10 low a appronimataly 90 siacharge LINE FAILURE PROTECTION Allows insirumen to be operaiag in LINE position with automatic awiich over to batery power it ting voltage tale OPERATING TEMPERATURE 0 jo 80 C POWER REQUIREMENTS Charging
12. QUENCY MEASUREMENT RANGE 10 Hs 10 10 Mt GATE TIMES Manually selected 0 1 1 10 seconds or AUTO OPEN CLOSE Tetaliziog RANGE 10 MHz mas EXTERNAL GATE Gate positive negative or zero vons sinusoidal Inputa or pulses vin frontpane BNC convois SPECIFICATIONS HP Model 5302A Universal Counter INPUT CHANNELS ANO B SENSITIVITY min 25 mV rma sine wave 60 He Yo 1 MHz 50 mV 1m sine wave 10 KE to 10 MHE 100 mV rma ain wave 1 50 MHz 150 mv p p pulse at minimum puise width 50 ra Sensitivity can be varied continuously up io 25 V mms by aahusting the SENSITIVITY contro IMPEDANCE 1 MO shunieg by Less than 30 pF TRIGGER LEVEL Selectable positive negative or zero volis FREQUENCY RANGE Channel A 10 Hs to 0 MHz presented by 10 Channel B 10 He to 10 MME GATE TIMES Manually selected 0 1 1 10 seconds or AUTO TIME INTERVAL RANGE 100 ne to 1000 second RESOLUTION 100 ns to 1 ms in decade aps PERIOD PANGE 10 Ke le 1 Mhz RESOLUTION 100 na 19 1 ma in decade top PERIOD AVERAGE RANGE 10 Me to 1 Ma PERIODS AVERAGED 1 to 10 automatically selected FREQUENCY COUNTED 10 Mite RATIO DISPLAY Fa Fa times multiplier N N in decade stepa RANGE Channel A 10 He 10 Me Channel B 10 He to 10 MME OPEN CLOSE Toteizing RANGE 10 MHz max PRICE 280 00 electatie HP Model 5303A Frequency Counter INPUT CHANNEL RANGE de to 500 MMs prescaind by 100 e 10 50 MMe prevealed by 10 SEN
13. SITIVITY imin 100 mV rme sine wave IMPEDANCE 500 OVERLOAD PROTECTION V 1m INPUT CHANNEL B RANGE 10 He Yo 50 MHz proncales by 10 10 Ma to 10 Mia direct SENSITIVITY min 50 mV me sine wave 20 He te 10 MME 100 mV ima wine wave 10 He fo SOMME 180 mV po puise st minimum puise width 20 ne 70 ne on 10 MME range Sensitivity can be varied continuosaty up 19 25 V x atterua tor saming ATTENUATOR 1 of 25 IMPEDANCE 1 MO shunted by laws than 40 pF TRIGGER LEVEL Selectable positive negative or jero voita FREQUENCY MEASUREMENT GATE TIMES 0 1 1 or 10 seconds PRICE 750 00 Acknowledgments The 5300 family was very much a team effort Lewis Masters was responsible for the 5301A and 5302A mod ules Ron Freimuth designed the 5303A in addition to creating the power supplies and the battery pack The 5304A was the work of Tom Mingle who also designed the control IC The mechanical design of the battery pack was contributed by Bill Anson We would also like to thank Steve Combs who gave us the 5301A prototype Of the many others who contributed their wisdom knowledge and hard work we would particularly like to acknowledge the help of Dexter Hartke Roy Ingham Dave Johnstone and Joe Elston References last summer and Iton Wang for his IC support 1970 12 Copr 1949 1998 Hewlett Packard Co HP Model 5304A Timer Counter INPUT CHANNELS amp AND B RANGE de coupled 0 to 10 Mie ae coupled 100 Hz to 10 MHE SE
14. al design Hendrick Swart for preamplifier and integrator product design Marv Underhill for his work on the ink writing systems and Tom Barker for his work on the chart drive im Follansbee for the Charles K Michener Chuck Michener received both his Bachelor of Science and Master of Science Degrees in Mechanical Engineering from the California Institute of Tech nology He joined the San Diego Division of Hewlett Packard Company after receiving his M S in 1966 Since then Chuck has been involved in mechanical design of recorder servo drives including the linear motor He was project leader for the development of the 7123A 7143A linear motor Strip Chart Recorders SPECIFICATIONS HP Model 7123A B and 7143A B Strip Chart Recorders INPUT RANGES Single span 1 mV 100 V specified by option TYPE OF INPUT Single ended floating INPUT RESISTANCE 1 M2 constant on all spans MAXIMUM ALLOWABLE SOURCE RESISTANCE R 10 ki un restricted for spans below 1 V NORMAL MODE REJECTION at line frequency gt 40 dB COMMON MODE REJECTION 100 dB at dc and 80 dB at line frequency RESPONSE TIME R lt 10 kit lt 1 3 s for 7123A B lt 1 4 s for 7143A B lt 1 2 s for spans below 1 V OVERSHOOT lt 1 ACCURACY 0 2 full scale ZERO DRIFT lt 0 005 C LINEARITY terminal based 0 1 full scale REFERENCE STABILITY 0 002 C CHART SPEEDS Speed determined by option choice CHART SPEED
15. alanced Power to recharge the battery pack comes from the mainframe power supply The requirements on this sup ply are quite severe Although the total power drain is usually only a few watts the tiny power supply in the mainframe has to be capable of powering many snap on modules with widely differing load requirements and of providing power to recharge the battery pack It has to operate from a wide range of ac power inputs or from the dc battery The power supply is therefore in two sections an ac transformer input which provides an intermediate de voltage and a high efficiency high frequency de to de converter An automatic SCR shutdown protects the supply and the circuits against overvoltages Safe Reliable and Serviceable When the mainframe is separated from the other mod Copr 1949 1998 Hewlett Packard Co ules an interlock circuit automatically shuts off the power to all exposed circuits This is one of the many safety features built into the instrument Another is the power line input the line voltage cannot be changed without first removing the line cord and the fuse Reliability is emphasized by the use of all solid state components a minimum number of parts and low power levels in all the circuits However in the event that a failure occurs serviceability has been considered in the use of sockets for all major IC and display modules Eric E May Rick May was responsible for the mechanical des
16. circuit and eight decade time base chips Counter chip top is 0 096 in by 0 118 in and contains 930 transistors Time base is 0 109 in square and contains 980 transistors The MOS process used by HP is low threshold p chan nel MOS 10 MHz speeds had never been achieved with this process before the six decade counter chip was de veloped The high speed comes from a combination of factors First the transistors in each of the six decades are made only as large as necessary for the counting rate at which they had to operate Only the first binary of the first decade actually has to operate at 10 MHz Second geometries are reduced to minimize capacitance Channel lengths are 2 5 jam after side diffusion and gate metal overlap is 1 25 m before diffusion Third the need for interconnecting metallization is minimized by a unique ground riveting process see Fig 5 What this tech nique does is eliminate all unnecessary ground lines to the sources of the MOS transistors An N region is diffused next to the P source diffusion and the two diffusions are connected by metal This connects the source to the substrate the other side of which is con Copr 1949 1998 Hewlett Packard Co Fig 5 Extra N diffusion next to P source and extra N guard band are elements of a unique ground rivet ing scheme that was used to eliminate much ground metallization This reduced the sizes of the MOS chips and allow
17. econds four months to 10 second resolution by proper interpretation of the display The 5302A is perfectly adequate for most timing mea surements but it is limited to measurements between the leading edges of two different signals Its two input amplifiers are ac coupled For better precision in timing measurements the 5304A module is more useful It can measure time between any two points on the same signal and it can select the precise voltage at which triggering occurs on the leading edge or the trailing edge of posi tive or negative signals Its two matched de coupled input amplifiers have bandwidths of 0 10 MHz they can also be ac coupled for measurements of signals with large de offsets In addition to timing events the 5304A can make measurements of pulse widths rise times and other in tervals between precise points on a waveform And that s not all Besides selecting the exact trigger point on an input waveform the 5304A can select which section of a waveform will trigger the stop channel This is the function of its delay control which allows it to perform measurements that are beyond the capabilities of most other timer counters Fig 8 Model 5304A Timer Counter snap on module is optimized for time interval measurements It has 100 ns resolution and an unusual delay feature which causes the counter to ignore extraneous events and measure the interval of interest Delay is useful for relay timing and t
18. ed 10 MHz speeds nected to the case which is grounded A source riveted in this manner is not actually grounded However it s separated from ground only by the series resistance of the source pad To reduce this series resistance a guard band of N material is diffused around the entire chip This reduces the series source resistance to approximately 800 ohms per square mil A load to source resistance ratio of 100 to 1 is used to assure sufficient noise rejec tion and the sizes of the source pads are adjusted accord ingly Using the riveting method throughout the circuit the design engineer for all practical purposes has the freedom to forget ground lines He no longer has to provide space for them This of course reduces the size of the chip and increases the speed Direct counting rates of 12 5 to 20 MHz are consistently achieved In a typical six decade counter with digit parallel binary coded decimal readout there are 24 outputs to the display driver This is too many for a compact pack age so in the 5300A a strobed readout is used the digits are read out one at a time on the same four lines Three input lines control the digit to be read out and the timing of the readout Thus the 24 lines are reduced to seven The time base divider in the 5300A is also a single MOS LSI chip measuring 109 mils square and contain ing 980 transistors see Fig 4 It also operates at 10 MHz consistent with the 5300A s 10 MHz crystal oscil lat
19. eet metal chassis as such the extensive use of LSI circuits and IC packages has made it possible to put all the circuitry in each module and the mainframe on one main PC board The PC board and the front and rear pane assemblies snap into a set of plastic clips in the casting This allows instant assembly or disassembly for servicing The case is designed for portability It is small and shaped so it can be carried readily in one hand This makes it easy to move around a bench there s no bothersome handle to fold out of the way Other units can be stacked on the case A tilt stand attached to the front feet is useful for normal bench viewing or it can be attached to the rear feet for easy viewing when the counter is placed on top of a cabinet or shelf For complete portability the power cord is disconnected and the battery pack is added between the mainframe and its functional snap on module There are handles on the sides of the battery pack and there s a shoulder strap for A Package for Portability and Serviceability carrying the counter or for draping it around one s neck for hands free operation The rear of the instrument has no protrusions so it can stand on end while on battery power Vacuum formed dust covers are provided with each snap on module to protect them and allow easy stacking when not in use Although designed for bench use and portable operation the counter can be rack mounted in a standard 19 in rack panel
20. f 200 turns with a circumference of 54 inches a coil current of 2 amps produces 1 2 pounds of axial force F BNIL are wound differently to assure similar dynamic per Bobbins of the 5 and 10 inch recorders formance Computer de was used to get the maximum axial force for the best motor geometry within the size limits o Magnet diameter and thickness for a the recorde given air gap were computed for the highest force Iron cross section areas A and A Fig 3 were made equal since both areas must conduct the same magnetic flux and A permanent magnet and the coil with sufficient clearance The annular gap between A contains the ceramic for free coil travel The relative areas of these four sec tions were calculated to provide maximum Bpm without saturating the iron at the ends of the linear motor Thus the motor has the highest permanent magnet field with the lowest possible servo amplifier power required Fig 4 ainic Magnetization curves and operating points of and ceramic magnetic material Conventional de alnico have small air gaps small magnet The linear motor has a large ts motors nd thick magnets and thin magne Ceramic permanent magnet material rather than al nico is used because it has a higher magnetic coercive force It is better adapted to a thin wall large magnetic gap and large area design Fig 4 Also it has a nearly Copr 1949 199
21. he entire dynamic range of the Models 7123A 7143A re corders are achieved with a new ink pump It is designed to use ink inertia and bobbin acceleration to maintain uniform ink pressure from the highest to the lowest pen speeds Electric writing is available as an option Fig 6 An all electronic integrator used for measuring the areas under the main trace is an option with the Model 7123A B recorders Its separate pen shares the slider rod and magnetic circuit of the linear motor with the main pen assembly Copr 1949 1998 Hewlett Packard Co Chart Drive The basic chart drive for the Models 7123A B and 7143A B recorders is single speed synchronous with line frequency A number of gear reductions are avail able for speeds from 6 inches per minute to 1 inch per hour An optional multi speed chart drive is also available Pulses from either an external or internal source are amplified and drive a stepper motor The internally gen erated pulses are provided by counting down from line frequency The drive then is synchronous with line fre quency With external pulses the data can be plotted against a variable other than time such as distance weight or fluid flow Acknowledgments I would like to acknowledge the valuable contri butions made by the following mainframe and preamplifier electrical design Steve White for the mainframe and integrator electrical design Lloyd Yabsley for the product and industri
22. ight side of chart Main signal recorded on 8 0 inch grid 10 major divi sions PEN LIFT Manual remote optional common with main pen PRICE Option 035 factory installed in 7123A B add 750 OEM Discounts available MANUFACTURING DIVISION SAN DIEGO DIVISION 16399 W Bernardo Drive San Diego California 92127 ACCURACY HEWLETT PACKARD JOURNAL AUGUST 1971 Volume 22 Number 12 FROM THE LABORATORIES OF HEWLETT PACKARD COMPANY 1501 PAGE MILL ROAD PALO ALTO CALIFORNIA 4304 LS A or Hemen Packard S A RH Smvser Esitoriat 8 Copr 1949 1998 Hewlett Packard Co enera Saitzeriand Yokagams Hewett Packard Lid Shi ns LD Shergaie Art Director Ari
23. ign of the 5300 system from initial concepts to production He joined HP in 1969 soon after receiving his B S degree in mechanical engineering from the University of Massachusetts A native of the New England area Rick says he came west because he enjoys California weather and attitudes Weather definitely plays a role in his major leisure time activities he likes camping tennis and skiing Diagnostics Finding the problem in a 5300 which is not working correctly is easy using the diagnostic kit Fig 11 This kit contains a set of simple PC cards and an interface connector which plugs onto the 5300A mainframe A set of diagnostic routines which are built into the mainframe circuits can be exercised by programming the mainframe from the PC cards Each card programs four tests these are called upon by plugging the card into the connector on each of its four edges in turn For example test 5 on card B makes a self check frequency measurement on the counter s own 10 MHz oscillator Test 4 checks out the by slowly cycling the numbers 0 through 9 in all s of the display A step by step diagnostic rou tine using only these four cards and the troubleshooting trees in the service manual can usually pinpoint the trouble down to the individual components without even opening up the mainframe If the mainframe checks out correctly it is then used to diagnose trouble in the snap Hans J Jekat Hans Jekat holds the e
24. k Model 5310A The benefits of modular construction are considerable Modularity makes it possible to choose from a wide range of measurement functions but to have at any one time only those functions necessary to do the job without the extra cost complexity and power consumption in this case battery drain of unused functions If and when a need arises new capability can easily be added to the system by adding more functional modules Adding these only when they are needed assures the user of always Fig 1 Compact low cost 5300 Measuring System consists of a maintrame top half of instru ment at left four snap on tunc tional modules and a battery pack right Autoranging serial BCD digital output and a high stability crystal reference oscil lator are standard having the latest in measurement capabilities at minimum cost Another economic advantage is that the mainframe can be produced in relatively high volume thereby bring ing its cost down The Mainframe The mainframe of the 5300 system is the upper half of the instrument All the elements necessary for a complete 10 MHz six digit counter are contained in this main module It houses the solid state display for the system all the basic counting storing and timing logic a high stability 10 MHz crystal controlled reference oscillator and all the functional control logic for precision counting and timing All the power for the system is provided b
25. ly extend this range The upper frequency limit at present is 500 MHz and is reached by adding the 5303A module The 5303A pre scales the 500 MHz input signal that is it divides the input frequency until it is within range of the 10 MHz mainframe counting logic Fig 7 Data comes out of the counter chip one digit at a time so the solid state display is scanned instead of continuously lighted One half digit is lighted at a time A scan is completed every millisecond so the display appears steady Copr 1949 1998 Hewlett Packard Co To extend the counting capabilities up to 500 MHz several new circuits had to be developed in HP s inte grated circuit labs The input signal is amplified by a thin film hybrid amplifier and trigger circuit A mono lithic 500 MHz binary and a 250 MHz quinary 5 divide the frequency down to a manageable 50 MHz These two high speed monolithic circuits are special EECL emitter emitter coupled logic circuits with two layer metallization In a six digit counter the effect of prescaling on mea surement accuracy is negligible Prescaling can sometimes be an advantage for measuring frequency modulated sig nals To fill all six digits in a direct count measurement a 500 MHz carrier frequency can be measured to six digit accuracy in 1 ms with 1 kHz resolution The same measurement with the 5303A takes 100 ms since the input is first divided by 100 But people don t respond to changes
26. mp for checking vital radio equip ment Shown here is all it takes a 5300A mainframe a 5310A battery pack a 5303A 500 MHz counter module and a makeshift antenna In this Issue Lilliputian Measuring System Does Much Costs Little by lan T Band Hans J Jekat and Eric E May page 2 A Package for Portability and Ser viceability LE DE D page 9 An Almost All Solid State Strip Chart Recorder by Charles K Michener page 13 HEWLETT PACKARD COMPANY 1971 Copr 1949 1998 Hewlett Packard Co ries and thin film hybrid circuits From the combined advantages of all these technologies this mini system de rives a level of performance that couldn t have been achieved at such low cost just a few years ago Modular design is apparent in the system photograph Fig 1 The heart of the system is a six digit counter mainframe Model 5300A which can be combined with any of several functional modules to meet specific appli cation needs The first four functional modules are now available see table page 4 There s a low cost 10 MHz autoranging counter Model 5301A a wideband 500 MHz counter Model 5303A a 50 MHz general pur pose universal counter Model 5302A and a precision timer counter specifically optimized for timing measure ments Model 5304A Any combination of mainframe and module can be instantly adapted for battery opera tion by inserting a rechargeable battery pac
27. nology The counting circuitry and the time base dividers have always imposed a limita tion on any counter based instrument in terms of per formance cost size and power drain In the 5300 system two small 16 pin packages containing MOS LSI chips have replaced what was previously half of the instrument Fig 3 Mainframe contains a complete six digit 10 MHz electronic counter except for an input amplifier and trigger Large scale and medium scale integration and a solid state display reduce the six major blocks in Fig 2 to just six components Benefits are reliability service ability and low power consumption A six digit counter like the 5 decade counting circuit and six decades of data storage The most common way of implementing such a circuit today would be with twelve TTL integrated circuit pack 300A requires a six ages However in the 5300A all six counting decades and six storage registers are on a single integrated circuit chip in a 16 pin ceramic package This metal oxide semiconductor MOS large scale integrated LSI cir cuit is capable of counting rates in excess of 10 MHz The chip measures 96 mils by 118 mils Fig 4 It contains 930 transistors but consumes only 300 mW It s an excellent example of the advantages of MOS LSI over bipolar IC s lower package count lower power con sumption and fewer interconnections to cause reliability problems Fig 4 10 MHz MOS LSI six digit counter
28. oded signals are also used to program the output frequencies from the time base In a low cost counter this bus oriented architecture represents a radical departure from the past It s signifi cant that the basic block diagram of a counter has re mained relatively unchanged for the last ten years surviving the major upheavals of technology from vacuum tubes to transistors to medium scale integrated circuits Now however with the advent of large scale integrated LSI circuits a break from tradition seems overdue When a few dozen extra transistors become insignificant compared with the cost of a few extra pins on an IC package design rules can easily be changed In the 5300 system the change was towards a greater emphasis on signal multiplexing and automatic operation Fig 2 Systems design results in a block diagram that s dit ferent from other counters All data is transmitted one digit at a time on a four line data bus The snap on module determines the function of the instrument Copr 1949 1998 Hewlett Packard Co The system approach resulted in reduction of all the counter logic to a simple combination of only five inte grated circuit packages see Fig 3 corresponding to the five basic blocks of the block diagram Fig 2 Inside each of these packages however is a very complex array of circuitry The LSI Circuits Two of these packages in particular represent a signifi cant advance in IC tech
29. of hands off operation Let s take a simple example see Fig 6 A frequency of 5 MHz is to be measured in the auto mode As the measurement proceeds cycles of the 5 MHz signal are accumulated in the counting circuits The measurement will be terminated after a precise measurement time for example one second to give a total count that can be interpreted as cycles per second or hertz The measure ment time is determined by the time base In one second however the 5 MHz signal would overflow the capacity of the six digit display therefore a shorter measurement time must be selected In this case a 0 1 second gate time would give an accurate six digit count of 5 00000 MHz Any shorter gate time such as 0 01 second would give a valid reading but would not completely fill the display As the measurement progresses the autoranging cir cuits detect when the first five digits of the display have been filled or more exactly when a count of 90 000 is reached In the case of the 5 MHz signal this would be after 0 018 second The next valid measurement time is then selected in this case 0 1 second The measurement time is always restricted to decade steps The MOS time base provides all the necessary timing signals beginning with a start pulse to initiate the mea surement This is followed by a succession of valid stop pulses at decade intervals of 1 us 10 us 100 ys and so Copr 1949 1998 Hewlett Packard Co Fig 6
30. one burst measurements Copr 1949 1998 Hewlett Packard Co The packaging of the 5300 system is a good example of today s demands on human engineering and industrial de sign The package had to be rugged portable and service able as well as have high performance and low cost The approach taken features a cast aluminum case for rugged ness and RFI shielding snap on modules rather than plug ins and snap together assembly for serviceability without a screwdriver The units are portable stackable and rack panel mountable The snap on concept was used for several reasons First there is no repackaging A normal plug in unit requires its own package which then must be insertable into a main frame package In the 5300 system the snap on module is simply a bottom half identical to the mainframe top half and together the two make up one complete package In addi tion there can be an in between module like the battery pack which fits between the mainframe and the snap on module In concept the counter could be expanded in definitely with a whole series of center modules Another advantage is that each snap on and in between module has its own rear panel which can change depending on its func tion The package consists of two half shells which snap to gether with two integral sliding latches The shel serves not only as a covering but as a chassis and RFI shield since it is made of cast aluminum There is no sh
31. or The time base chip has eight decades thus it can divide the 10 MHz crystal oscillator frequency by as much as 100 million to provide gate intervals as long as 10 seconds To reduce the pin count and take advantage of the LSI technology the architecture of the time base was changed from the traditional divider chain One change is that the time base output frequency is selected on the chip and is programmed by a three wire select code to divide the time base input frequency by any decade factor from 10 to 10 However the major distinction from all previous counting instruments is the second time base output which produces a logarithmic train of pulses This is the key to the autoranging feature of the instrument Autoranging One of the major features built into the LSI circuits is the capability of making measurements automatically so the operator doesn t have to change ranges Auto ranging which is built into the mainframe allows the display to be filled for maximum resolution but prevents the display from overflowing In the case of a frequency measurement this means automatically selecting the opti mum gate time For a period average measurement the optimum number of periods to be averaged is selected In either case the decimal point is positioned automatically and the correct measurement units are displayed Three of the four snap on modules make use of this feature to simplify the function controls and provide foolpro
32. ounce A delay output and a gate out Copr 1949 1998 Hewlett Packard Co put available at rear panel connectors can be used to intensity modulate an oscilloscope to show the exact in the duration of a tone ternal being measured Similarl burst can be measured by beginning with a long delay and decreasing it until the stop channel is triggered by the last cycle in the burst The delay time itself can also be measured precisely in the check mode This provides a convenient way of using the 5304A as a digitally calibrated delay generator since the delay output is available at a rear panel BNC connector Printing Out the Data Parallel Optional Data being measured by the be recorded on a digital printer like the HP 505 300 system can easily A or accepted by a computer A standard rear panel data out put sends out the buffered information in a digit serial bit parallel binary coded decimal format The output is synchronized with the scanning of the display Conver sion to an optional parallel format is provided by an accessory cable Model 10533A The serial to parallel stic hous the converter circuitry is in a small pl remote end of the cable Fig 9 Two advant s of this method are the lightweight flexible cable with only a few conductors and a wide rang e of possible formats to which the serial data can be converted A feature of the data output is the floating decimal point which
33. power vin 8300A malnirame nominal 7 5 wena WEIGHT Net 5 1b 2 3 Hal DIMENSIONS Banery pach pluga Delwenn 5300A maintrame anc plugon module Increases height of Instrument by 1 5 in B84 me PRICE 175 00 MANUFACTURING DIVISION SANTA CLARA DIVISION 5301 Stevens Creek Boulevard Santa Ciara Caiforna 98080 1 L T Band H J Jekat and J B Folsom Three new tech nologies converge in high performance instruments Elec tronics April 26 1971 2 M Brooksby R Pering and R Smith Fast logic extends range of high frequency counters Electronics December 7 An Almost All Solid State Strip Chart Recorder Linear motor pen drive replaces complex servo system with only one moving part By Charles K Michener ADAPTING A LINEAR MOTOR to a small strip chart re corder has resulted in a family of low silhouette recorders for dedicated applications These new Hewlett Packard Model 7123A B and 7143A B Strip Chart Recorders Fig 1 are only 3 inches high Small size and high reliability is achieved largely because the linear motor has only one moving part the slider pen assembly is the motor armature which slides back and forth over the length of the fixed cylindrical stator This is similar to the mechanism of electromagnetic loud speakers and solenoids except that the armature travel is much greater The Model 7123A B uses chart paper with a Fig 1 This new Hewlett Packard Model 7123A
34. quivalent of a B S degree from a technical school in Munich After moving to the USA in 1958 he designed mobile telephone equipment for four years then switched to linear integrated circuit develop ment He joined HP in 1964 to work in counter design but his last few years have been occupied with developing the MOS LSI circuits that made the 5300 system possible Hans has several patents and a profes sional paper to his credit He recently built his own home and he has a rather unusual on module avocation training show horses i lan T Band lan Band is project manager for the 5300 system A native of Scotland lan received B Sc and B Sc Honours degrees in physics from the University of St Andrews in 1957 and 1958 He came to the United States in 1963 and joined HP in 1965 to take charge of the first HP integrated circuit design section After designing many special IC s for several HP counters it was a logical step for him to begin designing complete counters and counter systems lan holds several patents and has authored two previous Hewlett Packard Journal articles He s a skier and he owns and races a 420 sailboat Fig 11 Diagnostic kit an accessory quickly pinpoints taults in 5300A maintrame 11 Copr 1949 1998 Hewlett Packard Co HP Model 5300A Measuring System Maintrame TIME Base CRYSTAL FREQUENCY 10 MWe STABILITY AGING RATE lt 3 pa
35. rts in 10 mo TEMPERATURE LINE VOLTAGE GENERAL DISPLAY Gudigit salid sisie LED display DISPLAY STORAGE Holds reading between aamolen RESET Front panmi puahbution switch OPERATING TEMPERATURE 0 la 80 C POWER REQUIREMENTS 113 or 230 volts 10 0 le 400 Hz 25 VA maximum depends on snap on modula Maintrame ower without ens 5 wars Battery operation With SSTOA rechargeable bate DIGITAL OUTPUT Digit serial 4 0 parallel BCO avaiable st tear panel connector CODE iime HOLDOFF Contact start of new measurement cy PARALLEL DATA OUTPUT Avaliable with Prinier Intertace HP 10599A ACCESSORIES AVAILABLE DIGITAL RECORDER INTERFACE Model 10533A 180 00 PACKAGE Contains an interlace card and rd for waxy troubleshooting of the S900 part in 10 for 10 line variations ate low TTL logie levain ind or TTL low level inhibite RACK MOUNT KIT 10573A single 10574A double Price 35 00 DIMENSIONS with plug on modula Haight 39 In 8 mm with 64 in 180 mm dapin DM In 248 mm PRICE 5195 00 HP Model 5301A Frequency Counter INPUT CHANNEL RANGE 10 Hs to 10 Mie SENSITIVITY min 25 mV rme sine wave 0 He to 1 MHE 0 mV rms wing wave 10 Mz to 10 MHz 180 mV pp pulse at minimum puise width 0 na Sensitivity can be varies cor wp to 25 V rme by adjusting the SENSITIVITY IMPEDANCE 1 MO shunted by lass than 30 pF TRIGGER LEVEL Seloctat tor optimum triggering ft FRE
36. y the high efficiency switching power supply in the main frame By itself the mainframe can perform no measure ments The bottom half of the instrument the snap on functional module calls upon the mainframe s capabili ties as needed for the particular application This parti tioning of capabilities maximizes the flexibility of the system In the simplest case the 10 MHz counter the snap on module consists merely of an input amplifier and trigger circuit to convert a low level input signal to a good logic level signal for the mainframe plus a hard wired program to tell the mainframe what to do with the signal Copr 1949 1998 Hewlett Packard Co The 5300 System 5300A MAINFRAME FOR USE WITH ALL MODULES sss 5310A BATTERY PACK FOR USE WITH ALL MODULES sms FREQUENCY PERIOD AVERAGE 125 250 750 300 System Architecture The 5300 is designed as a system from the ground up The system approach is evident in the architecture of the mainframe The block diagram Fig 2 shows the main frame coupled to a typical snap on module All data is transmitted one digit at a time digit serial on a four line data bus Data can be moved from the mainframe to the module and vice versa and from either location to the front panel display and to the rear panel recorder output The flow of data is controlled by a set of address codes which can be manipulated by the snap on module C
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