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1 Introduction 3,1 1 General Description 3,1 2 Specifications 3. 1 3 Power Unit 4,1 4 Circuit Description 4,1 5 Applications 4. 2 Operation 5,2 1 Operating Procedure 5,2 1 1 Operating Position 5. 2 1 2 Output terminals 5,2 1 3 Case terminal 5,2 2 Front Panel Controls 5. 2 2 1 Supply on off 5,2 2 2 Output polarity 5,2 2 3 Battery level 5.
2 2 4 Output voltage range 5,2 2 5 Output level 5,2 3 Output noise 6. 2 4 Common mode noise 6,2 5 Thermal emfs 6,2 6 Fuses 6. 2 7 Mains Power Unit 7,2 7 1 Type PU2 7,2 7 2 Constructional details PU2 7. 2 7 3 240V to 110V conversion 7,3 Constructional Layout Details 8. 3 1 Chopper amplifier module 8,3 1 1 Description 8.
3 1 2 Module replacement 8,3 2 Recalibration 9,3 2 1 Zero 9. 3 2 2 Full Scale 9,3 2 3 Calibration Procedure 11,3 2 4 10mV and 1mV Range Calibration 11. 4 Guarantee Servicing 12, All Time Electronics instruments are subject to continuous development and improvement and in. consequence may incorporate minor detail changes from the information contained herein. 1010 Technical Manual 2,1 Introduction,1 1 General Description. The 1010 is an accurate battery mains powered voltage calibrator sourcing up to 10 volts in. 5 ranges with a resolution up to 0 01uV, A precision zener reference diode is used as a basic reference source and low temperature.
coefficient resistors are used Power is provided by a mains rechargeable battery power. unit A front panel indicator monitors the battery condition The completely solid state circuit. design provides automatic standardisation against the internal reference and allows up to. 30mA output current with less than 0 1 ohms output resistance Short circuit overload. protection and a normal off reverse switch are provided. 1 2 Specifications,Ranges 0 9 9999V in 5 ranges,0 9 9999V in 100uV steps. 0 999 99mV in 10uV steps,0 99 999mV in 1uV steps,0 9 9999mV in 0 1uV steps. 0 999 99uV in 0 01uV steps, Accuracy 10V 1V ranges 0 02 of setting 0 005 of range. 100mV range 0 05 of setting 0 005 of range 1uV, 10mV 1mV Ranges 0 05 of setting 0 005 of range 4uV. Setting Resolution 5 digits, Output Resistance Less than 0 1 ohm type 0 05 ohm on 10V 1V and 0 1V ranges.
1 ohm on lower ranges, Maximum Output 25mA max on 10V 1V 0 1V ranges an internal short circuit current. Current limit is set at approx 30mA Lower ranges can be loaded up to the. short circuit current value although it should be noted that loads less. than 1000 ohms will give greater than 0 1 error, Maximum Overload The instrument can withstand a continuous short circuit on the output. Output Voltage Less than 30 ppm C to 50 C, Stability Less than 20 ppm V variation in supply voltage. Less than 75 ppm year not cumulative,Less than 10 ppm hr at constant temperature. Output Polarity Positive or negative switch selected A centre off position on this. switch provides a short circuit on the output for 1010 voltage source. Output Noise Level 10 1 0 1V ranges less than 10 ppm of setting 2uV 0 10 Hz. 10mV 1mV ranges less than 0 05uV 0 10 Hz,Dimensions 20 x 160 x 190 mm.
Weight Approximately 3 3kg,1010 Technical Manual 3. 1 3 Power Unit, The 1010 is supplied with a mains battery power unit This can be configured when ordered. for either 115V or 230V AC 50 60Hz See section 2 7 3. 1 4 Circuit Description, The calibrator employs a temperature compensated zener diode as the basic reference. source This provides the input to a FET chopper amplifier system which operates in a feed. back stabilised mode and has a gain value determined by a set of precision metal film. resistors which are selected by a 5 decade thumbwheel switch The output voltage is. variable from 0 to 9 9999 volts in 5 ranges An output resistance of typically 0 05 ohms is. maintained on the top three ranges the maximum output current that can be drawn on. these ranges is automatically limited to 30mA This is to prevent damage to the circuitry in. the event of accidental short circuit etc, The lower ranges have an output resistance of 1 ohm and will supply current up to the short. circuit value To ensure complete reliability the range switch employs two contacts in parallel. for each position even if a contact fails the 1010 still functions correctly. 1 5 Applications, The uses of the instrument include the calibration applications of conventional voltage.
potentiometers A 1010 in these applications has the advantage of requiring no. standardisation and being able to supply much higher output currents without loss of. accuracy Long term stability is inherent since standardisation is not required. Other applications as a precision voltage source include calibration linearity and gain. stability measurements etc on D C amplifiers digital and electronic voltmeters. transducers and as a variable low current power supply or backing off voltage The 10. ppm HR stability and low noise levels are of particular interest when an extremely stable. voltage is required rather than a high accuracy calibration source. 1010 Technical Manual 4,2 Operation,2 1 Operating Procedure. Operation of the 1010 is self explanatory from the front panel controls and specification. Normal precautions concerning overload and incorrect range etc should be observed. Battery condition should be checked on the front panel display before and during use. For quick zeroing of output set the Polarity switch to OFF This applies a short on the. output terminals,2 1 1 Operating Position, Unlike many potentiometers and devices incorporating Standard Cells the 1010 DOES NOT. require operation or transportation in a particular position. 2 1 2 Output terminals, The selected output voltage is connected to the front panel safety terminal binding posts. which are suitable for normal wire compression connection or by 4mm plug insertion. 2 1 3 Case terminal, The case terminal is connected only to the instrument case and is isolated from the circuitry. The case provides an overall electrostatic screen for the 1010 and can be earthed as. required to improve rejection of noise pick up,2 2 Front Panel Controls.
2 2 1 Supply on off, A miniature toggle switch interrupts the supply line to the circuit module Indication of supply. on off is provided by the battery level indicator,2 2 2 Output polarity. A change over toggle switch enables the output polarity to be reversed A centre position. provides a short circuit on the 1010 output terminals. 2 2 3 Battery level, The battery level is continuously monitored on a front panel indicator which also serves as a. supply on off indication A minimum mark indicates when the batteries need replacing or. recharging,2 2 4 Output voltage range,Selected by a 5 position rotary switch. 2 2 5 Output level, Selected on a 5 digit thumbwheel switch The resolution of setting is 0 01 of full scale.
1010 Technical Manual 5,2 3 Output noise, The electrical noise on the output voltage consists of chopper intermodulation thermal noise. and random variations Thermal noise becomes more significant on the lower ranges see. Thermal EMFS In general the total noise level is less than 20ppm of setting 2 uV for the. 10v 1v and 100mV ranges over the frequency range 0 10 Hz and less than 0 2uV 0. 10 Hz for the lower ranges Lower noise levels can be obtained by connecting a low pass. filter on the output terminals,2 4 Common mode noise. Additional noise and variation of the output voltage can be caused by large common mode. voltages These occur when the 1010 is used to calibrate or measure any input which is. above ground potential or has an a c component with respect to ground When battery. powered the 1010 has inherently a very high d c common mode rejection but it is not. recommended that 100V d c common mode be exceeded The a c common mode rejection. is determined by the capacitive unbalance to ground of the output terminals and associated. connections The 1010 is checked before despatch with 30 Vp p 50 Hz common mode. voltage on the output terminals,2 5 Thermal emfs, When the 1010 is used to provide precision voltages of less than about 1 mV care must be. exercised to avoid errors due to thermal emfs These occur where temperature differences. are present at the junctions of dissimilar metals e g a normal solder to copper junctions has. a thermal emf of approximately 3 uV C Errors inside the 1010 under temperature stable. conditions are typically less than 0 2uV, The power supply and output fuses are mounted on the INSIDE of the front panel printed. circuit board Access is by removing the instrument front panel as described in Section 3. Both are 20mm 250mA types Spare fuses can be obtained directly from Time Electronics. Ltd from your local supplier or an authorised distributor. 1010 Technical Manual 6,2 7 Mains Power Unit,2 7 1 Type PU2.
The PU2 incorporates a rechargeable Nickel Cadmium battery and electronics charge. control circuitry The circuitry is arranged to enable the PU2 to provide power directly from. the mains if the mains input is connected or alternatively from the rechargeable battery if. mains is not connected, When the mains is connected the charging circuitry provides the correct charge current 40. 45mA for the battery and automatically reduces this to a trickle rate 3 4mA when the. battery is fully charged This means that it is impossible to overcharge the battery. The DC performance is as follows, With mains connected DC output 15 5 7V 0 100mA load. With mains disconnected and battery fully charged DC 14 5 15 5V 0 100mA load. Mains input range 110 250V AC 40 60 Hz IEC mains input fuse is 20mm F1A. The capacity of the rechargeable battery is approximately 450mA Hrs This allows about. 40 50 hrs continuous use of the 1010 To fully recharge the battery requires 14 16 hours. with mains connected,2 7 2 Constructional details PU2. The P C B is located on the rear panel by 4 screws and is spaced off approx 10mm A. metal cover protects and screens the P C B and components The output connectors and. output fuse are located outside the cover The cover is fixed to the rear panel by a 4 screws. Later versions of PU2 have a 20mm F500mA fuse located inside cover. Important Note Take care when checking and dismantling a PU2 Even though. disconnected from the mains there is still sufficient power stored in the rechargeable. battery to cause catastrophic damage to the electronic circuitry if inadvertent short. circuits occur These can easily occur when the metal cover is being removed. 2 7 3 240V to 110V conversion, The PU2 mains transformer has tappings for 240V or 110V AC mains The following. procedure should be adopted to convert from 240V to 110V. 1 Remove mains power unit from 1010,2 Remove P C B metal screening cover.
Note Take care not to short any part of the circuitry when converting a PU2. 3 Connect mains transformer windings in parallel by rewiring the mains input to the. transformer As shown on the side of the transformer. 4 Replace the screening cover,1010 Technical Manual 7. 3 Constructional Layout Details, The complete instrument assembly except the Power Unit is mounted on the front panel. A printed circuit board which carries the components and range switch is located. immediately behind the front panel The panel and p c b can be removed as follows. 1 Remove Power Unit located in instrument rear by 4 screws. 2 Disconnect supply connected to power unit by 2 press stud connectors. 3 Remove front panel locating screws, 4 Withdraw front panel and p c b the power supply lead can also be withdrawn through a. hole in the plastic power supply cover, For recalibration the power supply can be connected without rehousing in the case. 3 1 Chopper amplifier module,3 1 1 Description, The module contains the F E T Chopper amplifier precision zener and associated circuitry.
It is a fully encapsulated module and connections are via a 16 pin connector moulded into it. The modular form of the 1010 s basic circuitry protects it from damage due to adverse. conditions and thermal gradients which could give rise to thermal emf errors A replacement. procedure should be adopted in the case of failure or malfunctioning of the module see. Section 3 1 2,3 1 2 Module replacement, 1 Remove and disconnect power unit located in instrument rear by 4 screws. 2 Remove front locating screws, 3 Carefully withdraw the front panel and associated printed circuit board p c b The power. supply lead can also be withdrawn through a hole in the plastic supply cover. 4 Remove 4 nuts which locate the module on the p c b. 5 Withdraw the module from the p c b, 6 Remove 4 nuts remaining on module mounting studs Put these nuts on the new module. Replace new module in reverse order ensuring the connector pins align correctly it may. be necessary to bend slightly the mounting studs in order to obtain smooth alignment of. the 16 pin plug and socket, Note It is important not to overstress the plug and socket since poor connection will result. 7 Adjust the position of the module above the p c b with 6 nuts on the module side of the. p c b When the module is parallel the plug and socket just closed the nuts on the. opposite side of the p c b can be tightened It is important to ensure that no strain is put. on the connector when the nuts are finally tightened. 8 Set Module zero and recalibrate as described on the following page. 1010 Technical Manual 5 2 Operation 2 1 Operating Procedure Operation of the 1010 is self explanatory from the front panel controls and specification Normal precautions concerning overload and incorrect range etc should be observed Battery condition should be checked on the front panel display before and during use

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