Time Electronics 1010DC User Manual

Time Electronics

1010 DC Voltage Calibrator

Technical Manual

V1.1 20/04/09 Time Electronics Ltd

Botany Industrial Estate, Tonbridge, Kent, TN9 1RH

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.TimeElectronic s .com

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C ontents

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

4. Recalibration .......................................................................................................... 9

4.1. Zero ......................................................................................................................... 9

4.2. Full Scale ................................................................................................................. 9

4.3. Calibration Procedure ...........................................................................................11

4.4. 10mV and 1mV Range Calibration ........................................................................11

5. 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

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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.

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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 feed­back 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

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