BK Precision 3010 User Manual

TEST INSTRUMENT SAFETY

WARNING

Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing must often be performed where exposed voltage is present. An electrical shock causing 10 miliamps of current to pass through the heart will stop most human heartbeats. Voltage as low as 35 volts dc or ac rms should be considered dangerous and hazardous since it can produce

a lethal current under certain conditions. Higher voltages pose an even greater threat because such voltage can more easily produce a lethal current. Your normal work habitis should include all accepted practices that will prevent contact with exposed high voltage. and that will steer current away from your heart is case of accidental contact with a high voltage. You will significantly reduce the risk factor is you know and observe the following safety precautions:

Don't expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equipment while making test connections in high-voltage circuits. Discharge high-

voltage capacitors after removing power. Use an insulated floor material or a large, insulated floor mat to stand on, and an insulated

work surface on which to place equipment; and make certain- such surfaces are not damp or

wet. Where insulated floor surface is not available, wear heavy gloves.

3. Use the time-proven "one hand in the pocket" technique while handling an instrument probe. Be particularly careful to avoid contacting a nearby metal object that could provide a good ground return path.

Always use an isolation transformer to power transformerless "hot chassis" equipment, where one side of the ac power line is connected directly to the chassis. This includes most recent television sets and audio equipment. Without an isolation transformer, the chassis of such equipment may be floating at line voltage (120 V AC, 60 Hz in USA), depending upon which way the 2-wire ac power plug is inserted. Not only does this present a dangerous shock hazard if the chassis is touched, but damage to test instruments or the equipment under test may result from connecting the ground lead of some test instruments to a "hot" chassis. The

ground lead of this function generator and most other test instruments with 3-wire power plugs is at earth ground.

S. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet.

This is a safety feature to keep the housing or other exposed elements at earth ground.

6. If possible, familiarize yourself with the equipment being tested and the location of its high votage points. However, remember that high voltage may appear at unexpected points in defective equipment.

Also remember that ac line voltage is present on some power input current points such as on. off switches, fuses, power transformers, etc., even when the equipment is turned off.

8. Never work alone. Someone should be nearby to render aid if necessary. Training on CPR

(cardo-pulmonary resuscitation) first aid is highly recommended.

FOR

.' .6460 W. Cortland Street

Chicago, Illinois 60635

INTRODUCTION SPECIFICATIONS. PANEL CONTROLS AND FEATURES. OPERATING INSTRUCTIONS

TABLE OF CONTENTS

PAGE

3 3

A. Frequency and Waveform Selection, Manual Operation

B. DC Output. C. Voltage-Controlled Operation. D.TTLOutput APPliCATIONS

A. Amplifier Frequency Response. B. Tone Control Test. .C. Amplifier Overload Characteristic. D. Amplifier Performance Evaluation Using Square Waves

E.SpeakerSystemTesting F.AMReceiverAlignment G. Using the 3010 As A Bias and Signal Source. H. Preset Frequency Selection. I. Digital Frequency Selection. J. Communications Receiver Alignment. K.AdditionalApplications THEORY OF OPERATION

GeneralCircuitDescription Detailed Circuit Description. MAINTENANCE AND CALIBRATION

Removal of Rear Case Calibration Procedure LineVoltageConversion WARRANTY SERVICE INSTRUCTIONS. ONE-YEAR liMITED WARRANTY.

8 9

16 18

2021

22 23 23

32 36

3738

INTRODUCTION

The B & K-PRECISION Model 3010 Function Generator is a versatile signal

source that can be used in a variety of engineering, industrial, educational and

hobbyist applications. The wide frequency range (.1 Hz to 1 MHz) for all functions

(sine, square, triangle and TTL output) encompassessubaudible, audio, ultrasonic and RF applications. The continuously variable DC offset control and provision for external VCO control further enhance the versatility of this instrument. The human-engineered case lends itself to bench use as well as easy portability.

SPECIFICA nONS

GENERAL

Basic Outputs

Square, sine, triangle, DC and TTL Square Wave

(separate output jack).

Frequency Range

OJ Hz to 1 MHz in six ranges.

External Frequency

Control

Maximum Input

Input Impedance

SPECIFICAnONS (AU specifications apply with dial scale between 1 and 10)

Dial Accuracy

Dial Range

VCO; greater than 100: 1 on any frequency range (linear). With FREQUENCY dial set at .1, a 0-to-5.5 V ramp input will produce a 100:1 fre-

quency change. Frequency increases with positive

voltage.

:!:20 V peak.

1000 ohms, nominal.

5% of full scale to 500 kHz, 8% of full scale from 500 kHz to 1 MHz (includes dial scale accuracy and range-to-range accuracy). Unit calibrated at full scale.

Greater than 100: 1,

Output Impedance Output Amplitude

Amplitude Control

600.Q, :1:5%.

20 V pop open circuit; 10 V pop into 600il.

Continuously variable, greater than 30 dB range.

DC Offset Continuously variable, :tIO V, open circuit; :tS V,

into 600Q.

V AC + Voc offset without clipping, :1:10 V

open circuit; :1:5 V into 600il.

Sine Wave

Distortion

Square Wave

Non-Symmetry

Triangle Wave

Non-linearity

Square Wave

Rise/Fall Time

Sine Wave Amplitude

flatness

TTL Square Wave

Response

Less than 1%, 1 Hz to 100 kHz; hannonics more

than 30 dB down from fundamental, 100 KHz to 1 MHz.

Less than 1 %, to 100KHz.

Less than 1%, to 100 KHz.

less than 100 nSEC at maximum output amplitude.

:1:.3 dB to 1 MHz at maximum output amplitude.

Less than 25 nSEC rise/fall time. Fixed TTL level: LO less than .4 V; III greater than 2.4 V. Will drive 20 TTL loads.

Short-Term

Stability

Power Requirements

Dimensions (HWD)

Weight

Handle

Max.

.05%

105 to 130 V AC, 60 Hz. 8 watts max. (105-130/210-260 VAC, 50/60 Hz export version

available)

3.2 x 11.3 x 7.7 (8.13x28.70x 19.56 cm.)

21bs.,9 oz. (1.16 Kg.) without line cord. 21bs., 14 oz. (1.31 Kg.) with line cord.

Four positions: integral part of case.

PANEL CONTROLS AND FEATURES

(See Fig. 1)

1. POWER on-off switch. Depressing this button turns the 3010 on. To turn off, push again and release.

RANGE selectors. Decade frequency type. Multiplying the range selected times the FREQUENCY dial (6) indication gives the output frequency, which applies

for all functions. For example, if the 100 K RANGE button is depressed and

the FREQUENCY dial is at 10, the output frequency is 1 MHz. FUNCTION selectors. Select square (IUU), sine ("",,), or triangle ("""")

output waveform which appears at 600n OUTPUT jack (9).

AMPliTUDE control. Controls the amplitude of the output signal, which

appears at 600n jack (9). This control does not apply to the DC OFFSET

voltage or to the TTL output.

S. DC OFFSET control. Adds positive or negative DC component to the signal

appearing at 600n OUTPUT jack (9). Continuously variable for :!:S V

(600 ohms) or :!:10 V (open circuit). The DC component added by this control is dependent of the adjustment of AMPLITUDE control (4).

FREQUENCY dial. Multiplying the setting of this dial times the frequency of the RANGE switch (2) selected gives the output frequency of the waveforms at the 600n OUTPUT jack (9) and TTL jack (7).

7. TI'L jack. A TI'L square wave is available at this jack. The frequency is determined by the RANGE selected and the setting of the FREQUENCY dial.

This output is independent of the AMPliTUDE and DC OFFSET controls.

8. -=b(Ground) jack. Common reference for the 1TL and 600n OUTPUT signals.

9. 600Q OUTPUT jack. Waveforms selected by FUNCTION switches as well as

the superimposed DC OFFSET voltage are available at this jack.

10. HANDLE. Multiple-position design permits use as a tilt stand or carrying handle.

(V)

--~

"""I'i

~" ,~,,';~

L!'),

CD,

CX)

' ""'."'."""";

1119,11

:D::::~::::

¥~:.'

[

jj:~:B

(.)

0')

11. VCO INPUT jack (rear panel). An external voltage input will vary the output

frequency. The change in frequency is directly proportional to input voltage;

therefore, the rate of change of frequency is proportional to that of the input

voltage.

12. LINE CORD RECEPTACLE (rear panel). This receptacle accepts the

detachable line cord. (Fixed power cord on 105-130/210-260 V AC, 50/60

Hz export version.)

Fig. 2. Rear panel.

OPERATINGINSTRucnONS

FREQUENCY AND WAVEFORM SELECTION, MANUAL OPERA nON

With the unit plugged into a power source, depress the POWER button (1).

2. Select the frequency range desired by depressing the appropriate RANGE switch. The frequency range obtained as the FREQUENCY dial (6) is varied will be from one-tenth the indicated RANGE value to 10 times this

value. For example, select the 10 K range. When the FREQUENCY dial is

at .1, the output frequency is 1 KHz; when at 1, it is 10KHz and when at 10 the frequency is 100 KHz. The frequency obtained applies to the signal

at the lTL jack as well as the 60012 OUTPUT jack.

Select the waveform desired by depressing the appropriate FUNCTION button. The phase relationships of the waveforms available are shown in Fig. 3.

4. The amplitude of the selected output signal at the 6001"2 OUTPUT jack is

adjusted by AMPLITUDE control (4). The TTL output is not affected by

the AMPLITUDE control.

A DC component can be added to the signal at the 600n OUTPUT jack by

use of the DC OFFSET control. The DC component introduced is

independent of the AMPLITUDE control and does not apply to the TTL

output. The level of DC can be varied :tIO volts open circuited or :tS volts across 600 ohms.

Fig. 3. Output waveform and phase relationships.

A. ZERO DC OFFSET

WITH MAXIMUM SIGNAL.

B. OFFSET LIMITS

WITHOUT CLIPPING

C. EXCESSIVE OFFSET,

-5V

DC OFFSET

POSITIVE

.--

NEGATIVE

DC OFFSET

Fig. 4. Use of DC OFFSET control.

Remember that the output signal swing of the generator is limited to :1:10 volts (open circuit) or :1:5 volts into 600 ohms. This applies to the combined signal and DC offset. Clipping occurs slightly above these levels.

Fig. 4 illustrates the various operating conditions encountered, when using the DC offset. If the desired output signal is large or if a large DC offset is

used, an oscilloscope should be used to make sure that the desired

combination is obtained without undesirable clipping.

When using the higher output frequencies and when using the square wave

and TTL outputs, terminate the cable in 600 ohms to minimize ringing.

Keep the cables as short as possible.

DC OUTPUT

The DC OFFSET feature can be used to convert the Model 3010 to a bipolar DC power supply with an internal impedance of about 600 ohms.

Depress the FUNCTION switches slightly so that all switches are released

(all buttons out). This removes all signal components from the output.

The output now consists of a DC voltage which can be varied continuously

from -10 volts to + 1 0 volts (open circuit) by use of the DC OFFSET

control.

A decoupling capacitor (20 mfd or more) can be connected across the

60012 OUTPUT and ground (-=:!::-) terminals to reduce the AC impedance of the output. Always observe polarity when using polarized capacitors.

VOLTAGE-CONTROLLED OPERAnON The 3010 can be operated as a voltage-controlled oscillator (VCO) by using an

external control voltage applied to the VCO IN jack at the rear of the unit. A male phono plug is provided for this purpose. The externally applied voltage will vary the frequency which is preselected by the RANGE switches and the FREQUENCY dial. A positive-going voltage will increase the frequency and a negative-going voltage will decrease the frequency. Please note that the

frequency does not change without limit as the input control voltage is increased. The upper dial frequency can be exceeded by about 10 per cent. If the control voltage reduces the lowest frequency available below the frequency corresponding to the low end of the frequency dial (.1), erratic operation

results.

The desired frequency, output waveforms, DC offset, and the output amplitud& adjustment are selected as for manual operation. The maximum

voltage-controlled sweep is over a 100:1 range.

SWEEP FREQUENCY OPERAnON

Select frequency range and function.

Set DC offset, if required.

Set amplitude to desired level.

To obtain maximum sweep, set the FREQUENCY dial to either

extreme. For this example, set at low end (.1 on FREQUENCY dial).

Connect a positive-going voltage to the VCO IN jack. A 0 to +5.5 volt ramp will provide a frequency increase corresponding to a FREQUENCY dial setting of 10. This is a 100:1 ratio. The frequency

varies in direct proportion to the applied input voltage.

FREQUENCY MODULATION

If an alternating voltage with no DC component is applied to the VCO IN

jack, the preset frequency will vary above and b~low the frequency that

was preset by the RANGE switch and FREQUENCY dial. The DC component of such an input signal can be removed by transformer or

capacitive coupling.

Select frequency and function.

b. Set DC offset, if required.

Set amplitude to desired level.c.

Adjust the VCO IN voltage to provide the desired frequency

modulation.

The approximate frequency deviation obtained for a given VCOsignal

can be determined as follows:

(1) .055 volt will produce a change in frequency equal to one per

cent of the highest frequency obtainable on a given range. For example, if the 1 K RANGE is selected and the FREQUENCY

dial is at 10, the output frequency is 10 KHz. One per cent of

10 KHz is 100 Hz. Therefore, for each .055 volt change in the VCO voltage, a 100 Hz change in frequency is produced with the 1 K RANGE selected, regardless of FREQUENCY dial setting.

(2) As an example, assume the RANGE switch and FREQUENCY

dial are set for 5 KHz output. If an alternating signal having an amplitude of :t.55 volt is is applied to the VCO IN jack, a

frequency swing of :t (:ih) 100 = :tl KHz is obtained. The table below indicates the frequency change per .055 volt input to the

VCO IN jack for each range.

Range,

100

Min.

Max.

KKKKKM

Frequency, Hz

(Dial at .1)

100

Frequency, Hz

(Dial at 10)

100

1% Frequency Change,

Hz (For .055 V input)

100

lOK

lTL OUTPUTD.

This is a fast rise time square wave output, available at the front panel. Because

of the fast transition times of this output, cabie termination should be

provided to minimize ringing. The output is always positive with respect to

ground. This signal can be' used as an external sync pulse for oscilloscopes when

using the other generator outputs. It also can be used as a variable frequency

signal source for exercising logic circuits.

1. Select desired frequency (repetition rate).

2. Connect to TTL output.

The AMPliTUDE and DC OFFSET controls have no effect on the TTL

output signal.

AMPUFffiR FREQUENCY RESPONSE (See Fig. 5)

Interconnect equipment as indicated Fig. SA. This use of either the oscil-

loscope or the AC voltmeter to measure output voltage is adequate. The

advantage of the oscilloscope is that waveform distortion can be

simultaneously monitored, particularly if a power response curve is being run. The AC voltmeter, provided with decibel scales, is convenient for converting the observed output variations into standard units of measure-

ment (dB). The amplifier under test may be anything from a single stage

transistor amplifier to a higi1 fidelity component type. The dual trace oscilloscope is convenient for this application because the -input to the

amplifier as well as the output c~ be monitored simultaneously.

Vary the frequency of the 3010 as required, maintaining a constant amplitude as observed on the oscilloscope. The amplifier input and output waveforms can be monitored simultaneously as indicated in Fig. Sb. Using two centimeters for amplitude references provides a convenient method of determining percent of change in amplitude.

The results of response tests can be plotted on semi-log paper as indicated

in Fig. 6.

TONE CONTROL TEST

If the amplifier under test is provided with base and treble controls, the effects of these controls on overall response can be determined by running consecutive response curves with the controls at both extremes of adjustment. The results can be plotted on semi-log graph paper, as indicated in Fig. 7.

C. AMPliFIER OVERLOAD CHARACTERISTIC

1. The overload point for some. amplifiers is difficult to determine exactly because of the gradual overload characteristic. The exact point of which signal compression begins is difficult to determine using sine-wave input. The triangle wave form is ideal for this type of test because any departure

from absolute linearity is readily detectable.

Using the test set-up of Fig. SA and using the triangle output, the peak overload condition for an amplifier can be readily determined. This overload condition is shown in Fig. 8.

APPLICATIONSA.

Select waveform

as required

No DC Offset

Dual Trace Oscilloscope preferred

\ I

~II DDDDD"DDDDD

-0

Termination

0"-

Amplifier under test

Output

A. TEST SET-UP.

; .C8)-1

.[[]. [[] .111...~

I-u=J -u

;r;::'1

--+--i

AC Voltmeter

B. WAVE SHAPE AND AMPUTUDE.

Fig. 5. Amplifier frequency response, manual frequency change.

.0D-1

..20"

In +...

-a

(/) +5

(/) 0

w -

> '

~ -10

-20.1

+201

~ ..101

L1J

II) 1

Z +51

Do I

ffi 0

L1J

> -5

L1J -10

FREQUENCY. Hz

Fig. 6. Plot of amplifier frequency response.

Fig. 7. Tone control effectiveness.

FREQUENCY, Hz

Input

Waveform

Output

Waveform

Fig. 8. Amplifier overload characteristics.

D. AMPliFIER PERFORMANCE EV ALUAnON USING SQUARE WA YES

The standard sine-wave frequency response curves, such as those obtained in Par. A, do not give a full evaluation of the amplifier transient response. The

square wave, because of the high harmonic content, yields much information regarding amplifier performance, when used in conjunction with an oscillo-

scope.

Use the test set.up of Fig. 9 A. This is

that a termination is specified at the;

using square waves to eliminate the

rise times. Using the triangle output of the 3010, set the AMPliTUDE control so

that there is no signal clipping over the range of frequencies to be used.

Select the square wave output and adjust the frequency to several check

points within the passband of the amplifier, such as 20 Hz, 1000 Hz and

10 KHz. At each frequency check point the wave form obtained at the amplifier

output provides information regarding amplifier performance with respect to the frequency of the square wave input. Fig. 9B indicates the possible wave forms obtained at the amplifier output and the causes.

Square wave evaluation is not practical for narrow band amplifiers. The restricted band width of the amplifier cannot reproduce all frequency

similar to that used in Fig. SA except

!mplifier input. This is essential when

ringing effects generated by the fast

components of the square wave in the proper phase and amplitude relation-

ships.

Dual Trace

rNo DC Offset

Oscilloscope preferred

-<>

-0

'-Square wave

selected

Amplifier under test

Termination

"'°1111

0-1

Output I

A. TEST SET-UP.

\;:~m.rn.-~ ~ .~

-t

B. TEST WAVEFORMS.

Fig. 9. Amplifier performance evaluation, using square waves.

1'7

SPEAKER SYSTEM TESnNGE.

The 3010 can be used to provide information regarding the input impedance of

speaker systems vs. frequency. In addition, the low-frequency resonance of the system can be determined. Because the Model 3010 output impedance is 600 ohms, which is much higher than the impedance of conventional speaker

systems, the 3010 can be used as a variable .frequency current source to

evaluate the input impedance of.the speaker system. This is shown in Fig. lOB.

Use the test set-up Fig. lOA. An oscilloscope could be used in this set-up

to verify that the 3010 is not being operated in a clipping condition.

Vary the frequency of the 3010 over the full range of interest and log the voltage measured at the speaker terminals vs. frequency. The dB scales of the AC voltmeter are convenient for converting this information to standard response units.

It will be observed that at some low frequency, a pronounced increase in

voltage will occur. This is th~ resonance frequency of the low-frequency

driver in the speaker system. This test set-up is convenient when designing speaker enclosures. It can help the designer to determine the effect on system resonance of varying port sizes, damping materials and other basic

enclosure factors.

The measurements obtained in the above tests can be plotted on semi-log

graph paper as indicated in Fig. IOC.

F-

AM RECEIVER AUGNMENT

Use the test set-up of Fig. 11. Because of the linear relationship between

sweep voltage and frequency of the Model 3010, a linear frequency presentation is obtained on the oscilloscope, regardless of whether the sweep voltage is a triangle, sine wave or a ramp.

To minimize the number of set-up adjustments required, the sweep voltage

to the VCO IN jack of the 3010 should not have a DC component. This can be removed by capacitor coupling.

If a precise center frequency is required, a frequency counter should be

used when setting the output frequency of the 3010. This is done without

sweep voltage input.

The sweep voltage to the oscilloscope can be supplied either to an external

horizontal input jack or, if the oscilloscope has front panel X- Y capability, it can be applied to one of the two vertical input jacks.

Fig. 10. Speaker system tests.

Because of the wide frequency range of the 3010, the signal can be

injected either at the mixer (455 KHz) or at the antenna (1 MHz). When injecting the 455 KHz signal at the mixer input, the local oscillator must be disabled.

When the IF response is observed at the input to the AM detector, an RF

detector probe is required unless a demodulated point is specified by the

manufacturer.

The IF amplifier tuning adjustments can be performed as required to

obtain the desired IF response curve. Normally each tuned circuit is adjusted for maximum amplitude at the IF center frequency.

Fig. 11. AM receiver alignment, RF and IF.

USING mE 3010 AS A BIAS AND SIGNAL SOURCE

In the test set-up of Fig. 12 the 3010 can be used to bias the transistor under

test as well as to furnish an AC signal. By observing the amplifier output on the oscilloscope, the amplitude and bias of the transistor can be optimized for maximum undistorted output. By use of the DC OFFSET control, the effects of various types of bias (class A, B, and C) can be determined.

DC Offset ~\

as required

Scope Sync

if required

Dual Trace Oscilloscope preferred

~ .. 1.=.:;m~]]-~-~;'

A+

wave seIec~ I

o4oj

Fig. 12. Use of Model 3010 as a combined bias'supply and signal source.

H. PRESET FREQUENCY SELEcrION

In test and design work where several frequencies are used repeatedly, it is convenient to be able to preselect these frequencies with a minimum of

effort. As shown in Fig. 13, the VCO feature of the 3010 can be used together

with preset voltages and frequency selector switch.

1. Set the FREQUENCY DIAL to .1. Connect the output of the 3010 to a frequency counter. With the frequency selector switch in the Fl position, adjust the Rl for

the desired frequency as observed on the frequency counter. Repeat this

for the frequencies desired. With the FREQUENCY dial set at .1, and a maximum available A+ voltage

of about 6 volts, frequencies encompassing a 100:1 range can be obtained by this method on each frequency range.

Fig. 13. Preset frequency selection.

DIGITAL FREQUENCY SELECTION Frequencies can be switched electronically by using the set-up shown in

Fig. 14. The preset voltages can be digitally selected and applied to the VCO IN jack on the Model 3010. Although provisions for two frequencies are shown, additional frequencies can be added using redundant circuits. This is

convenient in frequency shift keying (FSK) systems.

+6V

Fig. 14. Digitally programmed frequency selection

COMMUNICAnONS RECEIVER AUGNMENT The test set-up of Fig. 15 can be used for alignment of communication receiver

IF's arid discriminators using the 455 KHz IF frequency. For accurate

frequency adjustments, a 455 KHz crystal control marker source should be

used.

The sweep voltage source is applied to the 3010 VCO IN jack and to the

oscilloscope X-axis input.

2. the IF response curve is indicated. In some receivers the IF selectivity is "packaged" which means all adjustments are preset. In this case the

receiver alignment can only be evaluated and verified without adjustment.

Where the tuned circuits are adjustable, the manufacturer's procedure

must be followed to insure that the proper overall response is obtained.

K. ADDInONAL APPliCATIONS

The triangle output of the 3010 can be used at its lowest frequencies to simulate a slowly varying DC source. This can be used to check threshold levels

of TfL and CMOS logic as well as voltage comparators. Chart recorders can be checked by this method. Analog meter movements can be exercised from zero to fu" scale to observe defects, such as sticky meter movements.

FM Receiver

435

Fig. 1 S. Alignment of communications IF's and discriminators.

~Jj~

-\j

455

THEORY OF OPERATION

GENERAL CIRCUIT DESCRIPTION (See Block Diagram and Schematic)

The basic waveform generated in the Model 3010 is the triangle wave. This is

accomplished by charging and then discharging a capacitor by equal magnitude currents. A dual comparator and flip flop determine whether the capacitor is being charged or discharged. When the voltage on the capacitor reaches the positive limit, the charging current is switched off and the capacitor discharges until the lower

limit is reached at which time the charging current is then reapplied. The output of

the dual comparator is a square wave.

To produce a sine wave, the triangle wave is shaped by a special amplifier.

Range switching is accomplished by changing the magnitude of the current sources

and the timing capacitor. Dial frequency tuning is done by changing the magnitude

of the current sources. A frequency change of over a 100:1 is possible with the

frequency dial. Below is a table of the capacitors and currents. used.

RANGE (100:1) Hz -10Hz

1Hz -100Hz

10Hz -1 KHz

100 Hz -10 KHz

KHz -100 KHz

10 KHz -1 MHz

CAPACITOR

3.31J.F (CI5)

3.3 pF (CIS)

033 .uF (C16)

033 JJ.F (C16) 16.5.uA -1.65 mA

325 pF(CI7, 18)

300 pF (C18)

CURRENT

1.65 IlA -165 IlA

16.5,uA -1.65 mA

65 JlA -165 JlA

.65 .uA -165 .uA

16.5 IlA -

65mA

The peak-to-peak voltage of the triangle wave generated is 2.5 V. The frequency of operation is determined by the currents, the capacitor value and the peak-to-peak voltage of the triangle wave.

f = (2)-ccr

Thus for I = 1.65 mA, C = 3.3 jJ.F and Vpp = 2.5 V

f = (2) (3.3 x 1 0~6) (2.5)

f= 100 Hz

DETAILED CIRCUIT DESCRIPTION A.

Frequency Control Voltage Reference (IC4B)

The Frequency Control Voltage Reference is composed of three trimpots (Rll, 12, 13), two resistors and IC4B, which divide the +15 volts supply and

provide a reference voltage of approximately + 12 volts to the Frequency Control Potentiometer. Each trimpot is adjusted to compensate for the

tolerance variations of the timing capacitors.

Amplifier (IC4A)

The tuning amplifier is provided to buffer the output of the Frequency Control Pot. This assures that this voltage will be as linear as the frequency pot RIOI itself. If not, Rl7 would be in parallel with frequency pot RIO 1 and the action of the frequency pot would be non-linear.

"-(Vpp)

1.65 x 10-3

Current Summing Amplifier (IC4D, Q3)

The current Summing Amplifier sums the current from the tuning amp and the VCO input. The current from the tuning amp is simply the voltage at its output divided by the value of R17 (2Kil), The current from the VCO input is normail.y zero. When a voltage is applied, the current into the summer is the voltage divided by R18 (lKil). For a 100:1 sweep, the voltage has to be approximately +5.5V. The output current (collector of Q3) creates a voltage

across R19 (1 K) that tracks the voltage of the tuning amplifier by a factor of

-%.

Current Source Driver (IC3D, Q4)

IC3D is an operational amplifier and. Q4 is an emitter follower used in

B.Tuning

conjunction with the operational amplifier. IC3D and Q4 are connected as a

voltage follower with a closed loop gain of + 1. The voltage of the emitter of Q4 follows the input voltage of pin 12. The voltage at the collector of Q4 tracks

the voltage at the emitter but is of opposite polarity. In tflis way the current source driver provides both current sources with equal voltages.

Positive & Negative Current Sources (IC3A, IC4C, Q5, Q6)

TIle current sources provide two switchable sets of currents,. IC3A and Q6 are connected as a voltage follower. The voltage at the emitter of Q6 is equal to the voltage at the input to IC3A (pin 3). The current, produced, -I, is equal to the -15 volt supply minus the voltage at the emitter of Q6, divided by the total resistance RTI (which equais R22 + R23). The current -101 is produced by the same voltage but R24 has been switched in paraUei to the sum of R22 + R23

and the total resistance is now the parallel combination RT 1 0 (R24 in parallel

with the sum of R22 + R23).

The voltage across R21 is equal and opposite to the voltage across R20. IC4C and Q5 are connected as a voltage follower similar to IC3A and Q6. The voltage at the emitter of Q5 is equal to the voltage at the input to IC4C (pin

10). The current produced is equal to the + 15 volt supply minus the voltage at the emitter of Q5 divided by the total resistance RT2 (which equals R25 +

R26). The value of RT2 is half the value of RT l' therefore the current is 21. Similarly, when the combination, R27 + R28, is switched in parallel to the combination R25 + R26, the total resistance is RT20, which equals R25 +

R26, in parallel with R27 + R28. The total current with RT20 is 201.

Diode Gates (05, 06)

The diode gates are silicon diodes D5 andD6. In the 1.100 and 10K range, the positive current source puts out 21 and the negative current source sinks -I current. The purpose of the gates is to either switch the output of the positive

current source to the capacitors to charge them, or to shunt the current so that

the negative current source can discharge the capacitors. The gates work as follows:

If the signal from the level detector is high-level TTL, +5 V, it

reverse-biases diode D6 and cuts it off. Diode D5 now becomes forward-biased and all the current (21) flows through D5. Since the

negative current source can only sink -I current, a net positive current, I,

is seen by the capacitors and they are linearly charged to produce a positive ramp.

If the signal from the level detector is low-level TTt, 0 V, it forward-biases diode D6 and the level detector sinks all the current (21), from the positive current source. Diode DS now becomes reverse-biased and no current

flows thru it. The capacitors now see only the negative current source with

-1 current and are linearly discharged to produce a negative ramp. In the 10, lK, and lOOK ranges the gates work exactly the same except that the

currents are now 10 times greater.

CT (CIS, 16,17,18)

The timing capacitors CT are chosen for such highly desirable qualities as:

Low dissipation factor.

Low temperature coefficient.

Long-term capacitance stability.

H. Triangle Buffer (Q7, Q8)

The triangle buffer has a very high impedance to minimize leakage currents and prevent loading of the timing capacitors. Q7 is a dual FET; one half is the high

impedance buffer to the capacitors while the other half provides temperature

compensation to the first half. Q8 is an emitter follower and is used to provide the necessary current to drive the level detector, sine shaper, etc. The three silicon diodes along with the base-emitter junction of Q8 shifts the triangle waveform seen at the emitter of Q8 up to four diode drops (about 2.6V) so

that the diode dates can switch properly with a TTL level signal from the level

detector.

Dual Level Detector & Flip-Flop (ICS)

The level detector senses the level of the ramp input (either positive or

negative) and switches output states when the input reaches anyone of two

voltage limit references. The device (75107) has a dual differential input

comparator stage and a dual three-input nand gate output stage connected as an R-S flip-flop. The input limit voltage references are set by two voltage

dividers on the tracking + 15 V and -15 V supplies. Resistors R32 and R33 set

+ 1.25 V for the minus input of one comparator. Resistors R34 and R35 set

-1.25 V for the plus input of the other comparator. C22 couples a small posi-

tive feedback from one output of the iine receiver (pins 5 & 9) to the inputs (pins 2 & 12) to speed up the switching.

TTL Buffer (IC6B, IC6C)

IC6B and 6C are half of a quad nand gate package. They are connected in

p'.frallel and provide a fan-out of 20 for the TTL square wave. This avoids any

loading on the level detector.

Square Wave Level Shifter (IC6A, IC6D)K.

The square wave level shifter shifts the DC level of the lTL output of the level

detector so that it is approximately symmetrical about zero. IC 6A and 6D are

connected in parallel. One set of inputs (pins 2 and 12) are switched so that the

level shifter operates only when the square function button is pushed on. Trimpot R42 provides an amplitude adjustment for the square wave.

L. Sine Wave Shaper (IC7)

The sine wave shaper takes a triangle wave input and non-linearly shapes it to produce a sine wave. Tfie shaper utilizes the non-linear relationship of a

differential pair of transistors. The output is taken from one collector of the pair and buffered and level-shifted by the two other transistors in the package IC7. Trimpot R52 adjusts the amplitude of the sine wave and R59 adjusts its DC level at the output. Trimpots R50 and R55 are adjusted to provide the lowest distortion of the sine wave.

Output Amplifier (Q9, 10, 11, 12, 13) The Output Amplifier consists of .a differential input stage (Q9 and Q10)

followed by a common emitter transistor, Q 11. The output from Q 11 is applied to a push-pull output stage (Q12 and Q13). Feedback is applied from the output to the base of Q10 by R70 and R69. The closed loop gain is

approximately 10. DC offset is obtained by applying the offset voltage to the base of Q1 0 also.

Power Supply (IC1, IC2, IC3B, IC3C, Ql, Q2, 01,2,3,4)

Power transformer Tl, bridges diodes Dl, 2, 3, 4 and fIlter capacitors Cl and

C3 generate +22 V and -22 V unregulated. The +22 V is applied to ICl, a

78L15A voltage regulator, which generates the + 15 V supply. The +22 V is also applied through R5 to IC2, a 78LO5A regulator, which generates the +5 V. IC3C and Ql comprise a -15 V regulator which is referenced to the +15 V via

Rl and R2. In a similar manner, IC3B and Q2 comprise a -5 V regulator which is referenced to the +5 V supply via R7 and R8.

MAINTENANCE AND CALIBRATION

The following instructions are for use by qualified personnel only. To avoid electric shock, de not perform servicing other than contained in the operating irtstructions unless you are quaIifiedto do so.

2. A shock hazard is present when the case is removed once the line cord is plugged into an AC outlet. Avoid touching the fuse or bottom of ilie circuit board in the area of the fuse or power transformer. The fuse has 120 V AC (240 V AC on export models) on it even when the

POWER switch is off.

Your B & K-PRECISION Model 3010 Function Generator was carefully checked and calibrated at the factory prior to shipment. Calibration of this instrument should not be attempted unless you are experienced and qualified in the use of precision laboratory equipment. Should any difficulty occur during repair or

calibration, refer to the warranty service instructions at the rear of this manual for information or technical assistance.

Screw

Fig. 17. Removal of rear case.

REMOV ALOF REAR CASE

To remove the rear case from the generator, proceed as follows:

Use a coin (a quarter works best) to remove the two screws that hold the handle to the case. Use caution to avoid losing the springs beneath the screws that hold the handle on the case. Remove the handle. The handle

may be reversed if the user desires; refer to Fig. 17.

Remove the two Phillips head screws from the rear case.

Slide the rear case from.the generator.

To re-install the rear case on the generator, follow the above procedure in reverse. When re-installing the rear case, be sure the printed circuit board

properly engages the slots inside the case.

CALIBRA nON PROCEDURE A. Equipment Required:

Tektronix Model 465 Oscilloscope.

Hewlett-Packard Model 333A Distortion Analyzer.

3. B & K-PRECISION Model 1820 Universal Frequency Counter.

600[2 Tenninating Resistor.

Procedure:

Remove 3010 rear case Refer to Fig. 17. Place the 3010 on an insulated surface. Plug the line cord into the

receptacle on the 3010 rear bracket, then plug the other end into a

120 VAC outlet.

Set up the 3010 controls as follows:

POWER. RANGE .

FUNCTION DC OFFSET AMPLITUDE FREQUENCY

100

TRIANGLE Centered Fully Counterclockwise

Refer to Fig. 18 for trimpot location and Table

for trimpot function.

~F1

~R52

~R55

iR50

~R59

Fig. 18. Trimpot location.

Trimpot No.

R26 R28 R42 R50 R55

R52

R59

R13 R12 Rll

Table I. Trimpot Function

Function

1 KHz Symmetry

10 KHz Symmetry Square Wave Amplitude Sine Distortion 1 Sine Distortion 2

Sine Wave Amplitude Sine Wave DC Level

10 K Range Frequency

1 K & 100 Range Frequency

10 & 1 Range Frequency

Symmetry Adjustments (Refer to Fig. 18 for location of Trimpots R26

and R28).

Terminate the 30 I 0 TTL OUTPUT with 6O0n an~ connect both channel

I and channel 2 scope probes to it. Set the scope controls as follows:

CH 1 VOLTS/DIV CH 1 COUPLING CH 2 VOLTS/DIY

CH 2 COUPLING CH 2 INVERT. .

VERT MODE ... A TIME BASE..

HORIZ DISPLAY

A TRIG MODE. ..

A COUPliNG. ...

A SOURCE A TRIGGER SCOPE

B COUPLING. ...

BSOURCE

INVERT ALT

.1 mS/DIV

{LOCK

KNOBS

AUTO

NORM (Important)

+ DC

STARTS AFTER DELAY

Adjust CH 1 and CH'2 position controls to center each trace and adjust A TRIGGER level for a stable trigger. The display should appear to be two squares in phase but since CH 2 is inverted and NORM source triggering is

used, what appears to be falling edge of CH 2 is actually the leading edge of the TTL OUTPUT .

Change HORIZ DISPLAY to A INTEN.

Use the B TIME/DIY KNOB (pull to unlock) and the DELAY TIME

POSITION CONTROL to center the intensified trace to the trailing edges

of the square waves. Continue until the B TIME/DIY setting is IllS/DIY.

Now change HORIZ DISPLAY TO B DLY'D and the display should show

an expanded view of the falling edges of the square waves.

Adjust Trimpot R26 so that the edges coincide.

Change the 3010 RANGE setting to 1 K and repeat the above procedure

but change A TIME/DIY to 10 pS/DIY and B TIME/DIY to .1 pS/DIY

and adjust Trimpot R28 sO that the trailing edges of the two square waves

coincide.

Amplitude Correlation and Sine Distortion Adjustments. Terminate the

3010 600Q OUTPUT with 600Q and connect channell scope probe to it.

Change the scope controls to the new settings as follows:

CH 1 VOLTS/DIY .

CH 1 COUPLING. .

VERT MODE. TIME BASE.

2V GND

CHI

1 mS/DIV

HORIZ DISPLAY.

LOCK

A KNOBS

Adjust CH 1 POSITION control to center the trace on the scope grid. Flip CH 1 COUPLING to AC. Push in the 3010100 RANGE button and rotate the 3010 AMPLITUDE knob clockwise until the triangle wave just touches the 0 and 100 dotted lines on the scope grid. Flip CH 1 COUPLING to

DC. Rotate the 3010 DC OFFSET knob until the triangle wave just

touches the 0 to 100 dotted lines on the scope grid.

Push in the 3010 SQUARE FUNCTION button. Flip CH 1 COUPLING to

AC. Adjust Trimpot R42 until the square wave just touches the 0 and 100

dotted lines on the scope grid.

6. Push in the 3010 SINE FUNCTION button. Connect the distortion analyzer to the 3010 600Q OUTPUT. Manipulate the distortion analyzer

for a minimum distortion reading. Adjust Trimpot R50 first, then Trimpot

R55, for a minimum distortion reading. Readjust both Trimpots R50 and R55 for a minimum distortion reading (must be less than or equal to

0.5%). Disconnect the distortion analyzer. Adjust Trimpot R52 until the sine wave just touches the 0 and 100 dotted

lines on the scope grid. Flip CH 1 COUPliNG to DC. Adjust Trimpot R59 until the sine wave just touches the 0 and 100 dotted lines on the scope

grid.

Frequency Adjustments.

Connect the counter to the 3010 600il OUTPUT. Set the counter to

PERIOD FUNCTION. Push in the 301010 K RANGE button and be sure

that the 3010 FREQUENCY dial is set to 10. Adjust Trirnpot R13 for a counter reading of 10.000 p.S. OK if counter reading is between 9.980 p.S

and 10.020 p.S:

Push in the 3010 100 RANGE button. Adjust Trimpot R12 for a counter

reading of 1000.00 JlS. OK if counter reading is between 998.000 JlS and

1002.00 JlS.

Push in the 3010 10 RANGE button. Adjust Trimpot R11 for a counter

reading of 10.0000 mS. OK if counter reading is between 9980.00.uS and

10.0200 mS. Disconnect the scope probe and counter from the 3010 600n OUTPUT.

Carefully re-install the rear case (refer to Fig. 17)

LINE VOLTAGE CONVERSION

The 105-130 volt, 60 Hz power transformer (065-137-9-001) used in the stand-

ard 3010 is replaced by a 105-130/210-260 volt, 50/60 Hz power transformer

(065-137-9-002) in the export version. The line cord in the export version uses

standard DIN color codes. The power transformer is normally prewired to

match the power source used in the country of original sale. The instrument may be easily coverted to the alternate line voltage. To convert from 210-260 volt operation to 105-130 volt operation, or vice versa, use the following pro-

cedure:

Remove case (Fig. 17).

2. Rewire power tans former for desired line voltage (Fig. 19).

Change fuse Fl (see Fig. 18 for location). Use 'I. A, 3AG slow blow for

105-130 volt operation, or ~6 A, 3AG slow blow for 210-260 volt opera-

tion.

Change line voltage label.

210-260 V AC

Fig. 19. Transformer wiring, export version.

4.,~

105-130 VAG

WARRANTY SERVICE INSTRUCTIONS

.Refer to the MAINTENANCE section of your B & K-Precision instruction

manual for adjustments that may be applicable.

2. If the above-mentioned procedures do not correct the problem you are experiencing with your unit, pack it securely (preferably in the original cart()n or double-packed). Enclose a letter describing the problem-and include your name and address. Deliver to, or ship PREPAID (UPS preferred) to the nearest B & K-Precision authorized service agency (see list enclosed with unit).

If your list of authorized B & K-Precision service agencies has been misplaced,

contact your local diskibutor for the name of your nearest service agency, or write

to:

Service Department

B & K-Precision Product Group

DYNASCAN CORPORATION

2815 West Irving Park Road

Chicago, Illinois 60618

LIMITED ONE-YEAR WARRANTY

DYNASCAN CORPORATION wanants to the original purchaser that its B & K-

PRECISION product, and the component parts thereof, will be free from defects in

workmanship and materials for a period of one year from the date of purchase.

DYNASCAN will, without charge, repair or replace, at its option, defective product or

component parts upon delivery to an authorized B & K-PRECISION service contractor or the factory service department, accompanied by proof of the date of purchase in the form of a sales

receipt.

To obtain warranty coverage, this product must be registered by completing and mailing the

enclosed warranty registration card to DYNASCAN, B & K-PRECISION, 6460 West Cortland

Street, Chicago, Illinois 60635 within fifteen (15) days from the date of purchase.

Exclusions: This wananty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. It is void if the serial number is altered, defaced or removed.

DYNASCAN shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.

This warranty gives you specific rights and you may also have other rights which vary from

state to state.

For your convenience we suggest you contact your B & K-PRECISION distributor, who may be authorized to make repairs or can refer you t~ the nearest service contactor. If warranty service cannot be obtained locally, please send the unit to B & K-PRECISION Service Department, 2815 West Irving Park Road, Chicago, Illinois 60618, properly packaged to avoid damage in shipment.

c~~ ~.T.T~aJ["'T.T'- DYNASCAN

~A ..Jll('fr-JI.11J'. CORPORATION

6460 W. Cortland Street

Chicago, Illinois 60635

@ 1981 .DYNASCAN CORP.

480-225-9-001 C

PRINTED IN U.S.A.

BK Precision 3010 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual