EU-80A Voltage Reference Source


The Heathkit model EU-80A Voltage Reference Source is a very accurate,
regulated variable DC voltage standard. It is designed for maximum
convenience and versatility. The pushbutton Function switches select the
mode of operation permitting the Voltage Reverence Source to be used as
a DC voltage standard; a 60 Hz signal source for oscilloscope calibration;
or a precision DC sum or difference source for voltage comparisons,
potentiometric measurements, and bucking voltage applications.

SPECIFICATIONS

OUTPUT
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Output Voltage  . . . . . . . . . . . . . . .  0 to 10 volts DC, regulated

Readout . . . . . . . . . . . . . . . . . . .  Directly indicated by four dials, viewed through panel apertures

Voltage Accuracy . . . . .. . . . . . . . . .  First two digits – 0.1% and third digit – 1.0%

Voltage Stability
	Short term  . . . . . . . . . . . . .  15 ppm/hr
	Long term   . . . . . . . . . . . . .  1000 ppm/mo

Voltage Regulation . . . . .. . . . . . . . .  Output potential will vary less than 0.05% with
					       a change in line voltage from 90 to 130 VAC

Output Current using Voltage  . . . . . . . .  0 to 10 uA in 1 Mohm position 
to-Current Accessory  . . . . . . . . . . . .  0 to 10 nA in 1 Gohm position

Output Current Accuracy . . . . . . . . . . .  1% in 1 Mohm position. Maximum load (R) to ground, 10 kohms
					       2% in 1 Gohm position. Maximum load (R) to ground, 10 Mohms

NOTE: Maximum E across the load must not be greater than 1% of the E applied to the Voltage-to-Current Accessory

CONTROLS
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Range Selector . . . .. . . . . . . . . . . .  Four positions with maximum outputs of 10 V,
					       1000 mV, 100 mV, and 10 mV respectively.
					       Output is indicated in panel aperture. Neon lamps
					       indicate location of decimal point

Voltage Selectors . . . . . . . . . . . . . .  Ten-position Kelvin-Varley voltage divider switches for
					       the first two digits, and a continuous adjustment for the third digit

Function Switches . . . . . . . . . . . . . .

	On/Off Pushbutton . . . . . . . . . .  Applies or removes AC power

	S/A +/- S Pushbutton  . . . . . . . .  Provides output of only the Source potential (S) or algebraically adds an A Input potential and the Source (S) potential

	DC-S / Chop-S Pushbutton . . .. . . .  DC-S provides a continuous Source-output
					       Chop-S produces a Source-output “chopped” at a 60 Hz rate
	
	+S / -S Pushbutton. . . . . . . . . .  Determines polarity of only the Source potential at the Output binding posts

	Zero Out Pushbutton . . . . . . . . .  Opens output circuit and shorts Output binding posts together

Calibrate Control . . . . . . . . . . . . . .  20-turn linear control on circuit board. Accessible from rear panel

GENERAL
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Operating Temperature Range . . . . . . . . .  10 degrees to 40 degrees C

Power Requirements . . . . .  . . . . . . . .  105 to 125 volts AC, 50/60 Hertz - 10 watts maximum

Fuses . . . . . . . . . . . . . . . . . . . .  AC line: ˝ ampere Slo-Blo
					       Output: 1/16 ampere

Dimensions  . . . . . . . . . . . . . . . . .  4-3/4” wide, 9-1/2” deep, 6-3/4” high

Net Weight  . . . . . . . . . . . . . . . . .  4-3/4 lbs. (including Voltage-to-Current Accessory)