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PRODUCT SHOWCASE Protek 505 digital multimeter has dual display This Protek 505 digital multimeter has a large dual digital display plus bar graph, true RMS readings, memory storage and 4000 count resolution. As well, it will measure temperature, frequency, capacitance and inductance. While all multimeters will perform voltage, current, resistance and diode tests, there are not many which can also measure temperature, frequency, capacitance, inductance, logic levels and dBm values. You can also measure time period for stop watch or alarm functions and store measured values in up to nine memory locations. The Protek 505 also includes a signal generator with three output frequencies (2048, 4096 and 8192Hz square wave). Naturally it is autoranging and this can be overridden if required. The Liquid Crystal Display (LCD) has a dual digital readout and bar graph plus numerous annunciators. This dual readout allows two measurements to be displayed and measured at once. For example, when measuring AUDIO TRANSFORMERS Manufactured in Australia Comprehensive data available Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 Ph (02) 476-5854 Fx (02) 476-3231 92  Silicon Chip frequency, the display will show the reading in Hz on the main display and the value of AC volts on the secondary scale. When the time display is selected, this is shown on the secondary scale with the measured value of volts, current, temperature or resistance on the main digits. There is no skimping on the size of the display either. The main and secondary display digits are 19mm and 9mm high respectively while the bar graph displays from 0 to 40 with 21 active segments. The word "active" is used because the display appears to have 37 segments, however, 16 of these are doubled up so that they are "lit" together. Knowing this is important for attempting to read the bargraph value. The bargraph is useful for seeing the trend of value changes which can be too fast for the digital display to update. The display can be backlit for use in dark locations. Most of the functions available can be manipulated to provide maximum, minimum, average and relative readings. These are accessed using the menu key. Once this key has been pressed though, there is no way out; you are stuck with selecting either Max, Min, Avg, Rel or Keep On unless power is switched off. We would prefer to have an Out selection which restores the meter to provide normal readings. The relative (Rel) display is useful when there is a fixed offset in the measurement. This can be subtracted so that only the change is displayed. Relative readings can also be displayed as a percentage change from the reference value. A hold feature freezes the display at any time so that no further changes in the reading take place. Readings can also be placed in memory for a more permanent storage. There are 9 memories available, labelled 1-9. The "0" memory location is innactive and cannot be used for storage. It can be recalled but it only shows 0000. The handbook indicates that this memory location is not useable, however, they also claim that there are 10 memory locations! The memory locations are not erased when the meter turns off in the auto power off mode. To prevent the meter from switching off after 30 minutes of inactivity, a "keep on " facility is available which disables the automatic power off. Naturally, the meter can be turned on and off at will using a separate push button switch. The handbook recommends switching off manually rather than waiting for the automatic power Optical light sources & power meter Tektronix has introduced a new line of handheld optical test products that include the TOP130, TOP140 and TOP150 optical light sources, the TOP200 power meter and the TOP300 visual fault finder. The TOP130 emits at 850/1300nm and is suitable for testing multimode cable used in LANs and WANs; the TOP140 laser source emits at 1310nm and the TOP150 laser source emits at 1550nm. Models TOP140 and TOP150 are used for testing single mode cables in Telco and CATV networks. All the light sources feature a off feature. This would be a good idea since battery life is only about 60 hours with a carbon zinc battery. Fortunately, a low battery warning indicator is included so that you will know when to replace it and a separate battery compartment is provided allowing easy access. Diode readings display the foreward voltage measured between anode and cathode on the secondary display. The main display shows either SHrt (short), OPEn or Good. These are supposed to tell you whether the diode is operating correctly. We found that good Schottky and high speed diodes universal connector interface for easy upgrade and cleaning. Battery life is claimed to be over 100 hours with standard alkaline batteries. A companion product to Tektronix optical light sources is the TOP200 optical power meter. It is a lowcost, palm-size unit that makes the basic optical power measurements in either dB or dBm, calibrated at 850nm, 1300nm and 1550nm. This power meter provides 0.01dB resolution and allows the user to store reference values for each wavelength independently. For further information, contact Tektronix Australia Pty Ltd, 80 Waterloo Road, North Ryde, NSW 2113. Phone (02) 887 7066. gave a "short" indication because their forward voltage was below 0.5V. The diode test provides up to 4V and so LEDs can be tested. The LED will light up and an open indication will be given because the forward voltage of the LED is greater than 1V. Some discretion must therefore be used when interpreting the short and open indications. Temperature sensing must be done using a "K" type thermocouple, which is available as an accessory. The probe can measure temperature from -20 to 1200 degrees C which is then shown on the main display. The secondary September 1995  93 Video magnifier uses CCD camera This 1/2" colour CCD high resolution video camera/microscope provides 10x, 20x and 40x magnification with greater than 450 lines horizontal resolution. The SVC-228 offers advantages over magnifying glasses and other optical inspection devices. Several or groups of people can simultaneously observe the image for discussion; images may be recorded on a VCR or by using an interface card stored, in a personal computer for documentation, manipulation, measurement or printout. The SVC-228 comprises a main unit which houses the power supply and interface circuitry and connects via a 2 metre cable to the camera head. Optional lenses provide a choice of magnification. Also available is an adjustable stand with lamps display shows the Fahrenheit value. With no probe connected, the readout will show ambient temperature and is useful for finding out why you feel cold (we reviewed this meter in winter!). While the meter can read inductance it is restricted values above 10mH which is a relatively large value in practice. Most inductances used in RF and switchmode supplies are much smaller than this. Note also that if the Q is less than 10 or the coil resistance is greater than 100W, then inaccuracies will result. Capacitance measurement range is better, at up to 100µF with a 0.01µF resolution. This means that you can measure 10nF and larger up to 99µF. Audio Lab for illumination. Applications include assembly and inspection of mechanical parts, components, surface mount devices, printed circuit boards, contacts, connectors, measurement, quality control and verification. For further information contact Allthings Sales & Services, PO Box 25, Northlands, WA 6021. Phone (09) 349 9413 or fax (09) 344 5905. We would have preferred to be able to measure much smaller values than 10nF (.01µF). The frequency meter mode can be used for measurement from 1Hz up to 9999MHz with 4 digit resolution. The input signal for the frequency mode is a minimum of 1.5V RMS (4.24V p-p). This is find for CMOS and TTL circuits but most analog and RF circuits will need a preamp/buffer for meaningful measurements. Incidentally, the meter incorporates a logic level range which indicates a logic Hi and logic Lo on the main display. The in-between voltage where the logic is indeterminate is indicated by a "....". Logic voltage is set for TTL levels and so it is suitable for High R.S.K. Electronics Pty. Ltd. Complete Audio Lab kit with PCBs, 1% resistors, PTH screened PCBs, IC sockets, boot Eprom, screen printed case, 8K RAM, 8031 processor and all ICs. Includes calibration and Audio Lab V5.1 software 10 VAC 1A plugpack plus socket $18. 2-Metre serial cable $9. $330 inc. tax. Processor test kit $15. Freight $9. Fully assembled & calibrated complete with plugpack (1-year warranty) $450 5 Ludwig Place, Duncraig, Perth WA 6023 94  Silicon Chip Phone (09) 448 3787 Speed CMOS as well. Three output frequencies are available from the meter. These are at 8192, 4096 and 2048Hz with a 4V p-p minimum output. The source impedance is 1.5kW so that it can drive logic circuitry. Interestingly enough, the signal swings between -0.7V and +3.3V. The is indicates that the internal signal generator must be AC coupled with a diode clamp to prevent the negative excursion going beyond one diode drop. Timer counting is available for up to 10 hours with a count rate of one second. You can count up from zero to 9Hr 59min 59sec and the alarm will sound one second after this maximum count has been reached. The counter is presettable to any time within this range. Counting down is also possible. In this case, however, the alarm sounds one second after 0.00.00 has been reached. AC voltage measurement is true RMS. This means that the correct reading is obtained for waveforms other than pure sine waves. On a normal meter without true RMS readings, the display is calibrated to give a correct RMS reading only for sine waves. With true RMS, the reading is essentially correct for other types of waves. For example, the additional error in reading compared to the sine wave for square and triangle waves is 0.2% and 0.3% respectively. For crest factors up to 2, the additional error is 0.5%. For accuracy details see the latter part of this review. Also on the AC voltage range is displayed a dBm reading on the secondary display. A reading of 0dBm means that the voltage is 0.7746V. This corresponds to 1mW into a 600W load and all dBm values displayed are referenced to this level. Continuity measurements are available with or without a tone. With tone selected the meter will register an OPEn condition above 100W and will show a short otherwise. Without the tone selected, the meter only shows the value in ohms. Accuracy The Protek 505 has ±0.3% +2 digits accuracy for the 400mV DC range. For the 4V to 1000V ranges, the accuracy is ±0.5% +2 digits. AC voltage accuracy is ±1% +3 digits for the 400mVAC range from 50Hz to 1kHz. The 4VAC to 750VAC ranges are ±1.5% +5 digits accuracy from 50Hz to 100Hz for the 4VAC range and up to 500Hz for the remaining ranges. Resistance accuracy is ±0.5% +2 digits up to 400kW and 1% +2 digits for ranges above this. DC current accuracy is ±1% +2 digits and AC current is ±1.5% +3 digits from 50Hz to 100Hz. This rises to ±3% +5 digits from 100Hz to 1kHz. Frequency accuracy is ±0.01% ±2 digits. Temperature accuracy is ±3% +5 digits from -20 to 10 degrees C. It is ±3% +3 digits from 10 to 350 degrees C. Capacitance accuracy is ±3% +5 digits and inductance accuracy is the same for values up to 20H. The meter is fully protected from over voltage and over current using fuses and a PTC thermistor. A spare 0.5A fuse is included inside the case, however, there is no spare 20A fast blow type included. The meter is supplied in a vinyl case which also holds the probe leads and handbook. The probes have two screwon aligator clips for the probe tips which are a worthwhile inclusion. In short, the Protek 505 is a lot of meter for the money. With true RMS measurement, dual display, bar graph and a host of measurement functions, it will be a popular unit. It is priced at $229 including tax and is available from Altronics in Perth or from their dealers Australia wide. Phone 1 800 999 007. Fast response oxygen probe Novatech Controls have developed a fast responding oxygen sensing probe for flue gas, furnace and kiln applications. The development program was in response to market demands from within Australia and overseas. The zirconia sensor has a response time in the millisecond region but is extended by the time taken to introduce the gas sample from the process to the sensor. This total speed of response time can be critical, particularly in automatic combustion trim systems. The Novatech development, which was the result of extensive wind tunnel testing, provides users with a probe which will respond to changes in the oxygen level of the sample within four seconds. It has an optional 10 micron particulate filter for flues with fly ash or other material which can block up sensing ports. The benefit to users of fast responding flue gas oxygen sensing probes is improved trim control of combustion air/fuel ratio. This means savings in fuel. In some critical cases where process measurement lag cannot be tolerated, automatic control may be implemented where it was not previously possible. Novatech oxygen probes use advanced zirconia cell technology developed by the CSIRO Division of Materials Science and Technology. For further information, contact Novatech Controls (Aust) Pty Ltd, 429 Graham St, Port Melbourne, Vic 3207. Phone (03) 9645 2377 or fax (03) 9646 3027. KITS-R-US PO Box 314 Blackwood SA 5051 Ph 018 806794 TRANSMITTER KITS $49: a simple to build 2.5 watt free running CD level input, FM band runs from 12-24VDC. •• FMTX1 FMTX2B $49: the best transmitter on the market, FM-Band XTAL locked on 100MHz. CD level input 3 stage design, very stable up to 30mW RF output. $49: a universal digital stereo encoder for use on either of our transmitters. XTAL locked. •• FMTX2A FMTX5 $99: both FMTX2A & FMTX2B on one PCB. FMTX10 $599: FMTX5 built and tested, enclosed in a quality case with plugpack, DIN input •connector for audioa complete and a 1/2mtr internal antenna, also available in 1U rack mount with balanced cannon input sockets, dual VU meter and BNC RF $1299. Ideal for cable FM or broadcast transmission over distances of up to 300 mtrs, i.e. drive-in theatres, sports arenas, football grounds up to 50mW RF out. FMTX10B $2599: same as rack mount version but also includes dual SCA coder with 67 & 92KHz subcarriers. • AUDIO Audio Power Amp: this has been the most popular kit of all time with some 24,000 PCBs being •soldDIGI-125 since 1987. Easy to build, small in size, high power, clever design, uses KISS principle. Manufacturing rights available with full technical support and PCB CAD artwork available to companies for a small royalty. 200 Watt Kit $29, PCB only $4.95. AEM 35 Watt Single Chip Audio Power Amp $19.95: this is an ideal amp for the beginner to construct; uses an LM1875 chip and a few parts on a 1 inch square PCB. Low Distortion Balanced Line Audio Oscillator Kit $69: designed to pump out line up tone around studio complexes at 400Hz or any other audio frequency you wish to us. Maximum output +21dBm. MONO Audio DA Amp Kit, 15 splits: $69. Universal BALUN Balanced Line Converter Kit $69: converts what you have to what you want, unbalanced to balanced or vice versa. Adjustable gain. Stereo. • • •• COMPUTERS I/O Card for PCs Kit $169: originally published in Silicon Chip, this is a real low cost way to interface •to Max the outside world from your PC, 7 relays, 8 TTL inputs, ADC & DAC, stepper motor drive/open collector 1 amp outputs. Sample software in basic supplied on disk. PC 8255 24 Line I/O Card Kit $69, PCB $39: described in ETI, this board is easy to construct with •onlyIBM3 chips and a double sided plated through hole PCB. Any of the 24 lines can be used as an input or output. Good value. Professional 19" Rack Mount PC Case: $999. •• All-In-One 486SLC-33 CPU Board $799: includes dual serial, games, printer floppy & IDE hard disk drive interface, up to 4mb RAM 1/2 size card. PC104 486SLC CPU Board with 2Mb RAM included: 2 serial, printer, floppy & IDE hard disk $999; VGA •PC104 card $399. KIT WARRANTY – CHECK THIS OUT!!! If your kit does not work, provided good workmanship has been applied in assembly and all original parts have been correctly assembled, we will repair your kit FREE if returned within 14 days of purchase. Your only cost is postage both ways. Now, that’s a WARRANTY! KITS-R-US sell the entire range of designs by Graham Dicker. The designer has not extended his agreement with the previous distributor, PC Computers, in Adelaide. All products can be purchased with Visa/Bankcard by phone and shipped overnight via Australia EXPRESS POST for $6.80 per order. You can speak to the designer Mon-Fri direct from 6-7pm or place orders 24 hours a day on: PH 018 80 6794; FAX 08 270 3175. Pattern generator for TV & computer monitors Obiat Pty Ltd has introduced the Black Star 1410 video monitor tester, a microprocessor controlled instrument for aligning and testing computer and TV monitors and video projectors. The comprehensive range of line and frame frequencies, together with the variety of rear panel outputs, ensure compatibility with the majority of computer monitors. The Black Star 1410 produces a wide range of test patterns which includes a testcard, raster, vertical and horizontal lines, colour bars, checkerboard, dots and a focus function. The selected pattern, system, sync. polarity and line/frame frequencies are shown on the unit's liquid crystal display. It is suitable for CGA, MDA, PGA, VGA, SVGA and 8514A/ XGA computer displays in addition to TV monitors. Factory-programmed versions of the 1410 are also available. For more information, contact Obiat Pty Ltd, 129 Queen Street, Beaconsfield, NSW 2014. Phone (02) 698 4111 or fax (02) 699 9170. September 1995  95