Time Electronics 1021DC User Manual

Time Electronics

1021 Current Source

With Null Measuring Facility

Technical Manual

V1.4 14/12/10 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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Contents

1. Introduction ........................................................................................................ 3

1.1. General Description ............................................................................................ 3

1.2. Specifications ..................................................................................................... 4

2. Controls .............................................................................................................. 5

3. Opera tion ............................................................................................................ 7

3.1. Preliminaries ....................................................................................................... 7

3.2. Normal Operation ............................................................................................... 7

3.3. Measurement of Current .................................................................................... 7

3.4. Voltage Compliance Adjustment - V O/P ...................................................... 7

3.5. Overload Conditions .......................................................................................... 7

3.6. Battery Recharging ............................................................................................. 7

4. E lectrical Nois e Pic k-Up .................................................................................... 8

5. Circuit Des cription ............................................................................................. 9

5.1. Power Supply ...................................................................................................... 9

5.2. Mains Recharger ................................................................................................. 9

5.3. Circuit Module and Range Switch ..................................................................... 9

6. Maintenance and R epair .................................................................................. 10

6.1. Maintenance ...................................................................................................... 10

6.2. Repair ................................................................................................................ 10

7. R ecalibration .................................................................................................... 11

7.1. Calibration Procedure ...................................................................................... 12

7.2. Linearity ............................................................................................................ 13

8. Guarantee & S ervicing ..................................................................................... 14

All Time Electronics' instruments are subject to continuous development and improvement and in
consequence may incorporate minor detail changes from the information contained herein.

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1. Introduction

1.1. General Description

• 100mA output with overload protection

• 0.02% Accuracy

• Wide range of applications

• Safety terminals

• Removable protective boot

• Battery level indicator

The 1021 is a precision DC Current Source suitable for calibration and test applications from
100nA up to 100mA.

The 100mA output with overload protection is based on the popular Time Electronics type
1007 millivolt source and incorporates many of the well-proven features. The instrument is
overload protected and a front panel indicator shows when insufficient drive voltage is
available. The terminal output voltage is adjustable between 14 volts and 40 volts, with a
maximum output power of 2.4 watts.

The unique circuit design ensures that it stays well within specification for at least 12
months. Variation with temperature is better than 60 ppm per ºC, and typically better than
20 ppm per hour at constant temperature. To improve the switch reliability, additional back­up contacts have been used – even if a contact fails, the 1021 will still operate correctly.

The accuracy and stability are such that a wide range of applications are possible. In the
process industries it may be used to test and calibrate current sensitive transducers, and
their associated indicating and recording instruments. The semiconductor industry requires
constant current sources for parameter measurements. It may also be used to measure DC
current accurately by using the null facility to back off the unknown current. Resolution of
1µA is possible.

The 1021 is housed in a robust metal case and a removable protective boot is supplied as
standard. The front panel safety terminals are compatible with 4mm shrouded plugs, as well
as standard plugs, bare wires, and spade terminals.

Rechargeable batteries give portable operation and a mains recharger is supplied with the
unit. Complete recharge time is 10-12 hours although sufficient charge for a few hours
operation can be obtained with only 1/2 hours’ charge. Overnight recharge is sufficient to
fully charge the batteries, which give up to 10 hours of typical operation. The mains
recharger is supplied as standard with the 1021 and connects with a socket on the top
panel.

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1.2. Specifications

Output: 0-100mA in 3 ranges:

(1) 0-99.99mA in 10uA steps
(2) 0-9.999mA in 1uA steps
(3) 0-999.9uA in 0.1uA steps

Accuracy: +/- 0.02% of setting +/- 0.02% of range
+/- 0.02uA

Drive Voltage: Adjustable between 14 and 40 volts.
Maximum output power 2.4 watts.

Out of Limit Warning: A front panel indicator provides indication of insufficient drive
voltage.

Output Polarity: Normal or Reverse, switch selected. A centre OFF position
provides an open circuit.

Output Stability: Better than 60 ppm per ºC (-10 ºC to +50 ºC). Better than 25
ppm per hr (at constant temperature).

Null Sensitivity: Adjustable from ±25mA to ±25uA.

Load Regulation: Better than 20 ppm per volt change in output.

Power Supply: 8 NiMH rechargeable batteries with external mains re-charger.

Standard mains voltage is 220-250V 50/60Hz.
100-125V 50/60Hz is available but must be specified on order.

Dimensions: 200 x 75 x 110mm
215 x 100 x 120mm including protective boot

Weight: 1kg

1.4kg including protective boot

Optional Extras: Leather Carry Case (9027)
Factory Calibration Certificate (9153)
UKAS Calibration Certificate (9105)
Additional Rechargeable Battery Packs:
230V mains charger and 8 NiMH cells (9529)
110V mains charger and 8 NiMH cells (9528)

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2. Controls

1

8
9

7

3

5

2

6

4

10

11

12

5

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