Farnell TOPS 3D - Page 2

The Farnell TOPS 3D bench power supply provides in one compact package, three power supplies
and digital metering of voltage and current.
A ten-turn potentiometer is used to adjust the bipolar tracking outputs of the 1 amp rails from 5 to
17 volts whilst a single turn potentiometer is used on the 4 amp supply to adjust the output from 4
to 6 volts. Both voltage and current of any one output can be simultaneously monitored on the two
digital meters by pressing the appropriate push button. When monitoring rapidly varying currents a
meter damping button can be pressed to minimise display flicker. If all three output select buttons
are released the voltmeter can be used to measure external voltages via front panel sockets. In this
mode the DVM is isolated from the outputs and can be floated up to 200V d.c. or a.c. peak from
earth. Maximum reading is 39.99 volts-useful for many on-the-bench applications.
Each output is provided with an output on-off switch with integral l.e.d. to indicate current overload.
All outputs have preset self-resetting current limit protection. On the 4 amp rail this has a fold-back
characteristic and this rail also has overvoltage protection which may be reset using the output
on-off switch.
The TOPS 3D is manufactured to the same stringent standards that have made the Farnell L series
analogue metered bench power supplies the most successful in Europe. The units meet IEC348 and
BS4743 safety reqirements.
Specification
Mains input 50/60Hz 110, 220 & 240V +10%
by internal tap change.
Outputs 4 to 6V at 4 amps. Tracking -5 to -17:;
+5 to +17 volts at 1 amp.
Voltage controls 4-6V single turn potentiometer.
5-17V 10-turn potentiometer.
Line regulation (0utput change for +10%
supply input change) Less than 0.05% output
+2mV
Load regulation (0utput change for zero to
full load change) 4-6V output: less than 0.2%
output +5mV 17-0-17V outputs: less than 0.05%
output +2mV.
Ripple and noise (At full loadA F - 80kHz)
Less than 2mV pk-pk.
Transient recovery time Typical
Less than 300uS for output to recover within
50mV following 10% to 100% load change of
1uS risetime.
Temperature coefficient Typical. 0.02% per °C
Working ambient temperature 0°C to 40°C.
Storage temperature -20C to 50°C
Represented overseas by
Printed in England 881
Overload protection Foldback current
limiting on 4-6V output. Current limiting on
17-0-17V outputs. Additional protection offered by
rear panel mounted fuses.
Overload indication Onset of limiting indicated
by LED mounted in OUTPUT ON/OFF switch
bezel.
Overvoltage protection SCR crowbar protection
on 4-6V output only.
Meters 4 Digit LED VOLTMETER and 4 Digit
LED CURRENT METER. Voltage and current
simultaneously monitored on any one output
selected by front panel push buttons. Voltmeter
only can be selected by same push buttons to
read external votages.
Current meter
Display: 4 digit, 12.5mm, high output red LED.
Range:0 to 3.999 Amps. (Overrange indicated by
OFL).
Resolution: 1mA.
Accuracy: +0.3% reading +0.1% full scale at 23°C
Damping: To ease the measurement of rapidly
fluctuating currents an increased time constant
can be switched in by depressing front panel
push button.
We reserve the right to amend spec1fications without nottticat1on.
Voltmeter
Display: 4 Digit, 12.5mm, high output red LED.
Range:0 to 39.99 volts. (0verrange indicated by
OFL).
Resolution: 10mV.
Accuracy: +0.2% reading +0.1% full scale at 23°C.
External voltage measurement By selection
of three push buttons the voltmeter can be used
to measure external voltages in the range O to
39.99 volts via 2mm front panel sockets. (Use
Vero 63-1864C plugs or equivalent).
Input impedance 1MQ approximately.
Isolation Input sockets to voltmeter are fully
isolated from power supply output terminals when
operated in external mode. The input terminals
must not float at greater than 200V peak from
any output terminal or chassis.
Dimensions Approx Overall
Height 169mm width 219mm depth 290mm.
Weight (approx) 7.4kg
Manutactured in England by
Farmell
FARNELL INSTRUMENTS LIMITED
SANDBECK WAY-WETHERBY
WEST YORKSHIRE LS22 4DH
TELEPHONE (0937)61961
TELEX 557294 FARIST G
REGIONAL OFFICE (SOUTH)
TELEPHONE:HARPENDEN (05827)69071
TELEX: 826307 FARINT G