VOLTEQ SFG1010 Function Generator User Manual

SFG1010 Function Generator
User Manual

FUNCTION GENERATOR

This instrument is a signal generator with features such as highly stable, broadband and multi-function .The design of appearance is strong and elegant. And it is easy to  operate, could directly generated sine wave, triangle wave, square wave, ramp, pulse, and has VCF input control functions. TTL / CMOS can be as synchronized output with  the OUTPUT. The adjusted Waveform is symmetry and have reverse output, DC level can be adjusted continuously. Frequency meter could be as the display of internal  frequency and measure the outside frequency. It is particularly suitable for teachings, scientific researching and experimenting of electronic and pulse circuits.

Main technical Features

1. Frequency range: 0.1Hz-2MHz (SFG1002)
   0.1Hz-5MHz (SFG1005)
   0.1Hz-10MHz (SFG1010)
   0.1Hz-15MHz (SFG1015)

2. Waveform: sine wave, triangle wave, square wave, Positive and Negative sawtooth and Positive and Negative pulse

3. Square-wave front: SFG1002<100ns
   SFG1005<50ns
   SFG1010<35ns
   SFG1015<35ns

4. Sine wave
   Distortion :< 1% (10Hz-100KHz)
   Frequency response: 0.1Hz-100 KHz ≤±0.5dB
   100 KHz-5MHz ≤±1dB (SFG1005)
   100 KHz-2MHz ≤±1dB (SFG1002)

5. TTL / CMOS output
   Level:TTL Pulse low level is no more than 0.4V, high level is no less than 3.5V.
   Rising time: no more than 100ns

6. Output: Impedance:50Ω±10%
   Amplitude: no less than 20vp-p （Empty load）
   Attenuation：20dB 40dB
   DC bias 0-±10V (Continuously adjustable)

7. Adjustment range of symmetry: 90:10-10:90

8. VCF input
   Input voltage:-5V-0V±10%
   The maximum voltage ratio: 1000:1
   Input signal: DC-1KHz

9. Frequency meter
   Measuring range: 1Hz-20MHz
   Input Impedance: no less than 1 MΩ/20pF
   Sensitivity: 100mVrms
   The maximum input: 150V (AC+DC) with attenuator
   Input attenuation: 20dB
   Measurement error: ≤0.003%±1digit

10. The scope of adaptation of power
    Voltage: 220V±10 %( 110V±10%)
    Frequency: 50Hz±2Hz
    Power: 10W (Optional)

11. Environmental conditions
    Temperature: 0ºC
    Humidity: ≤RH90% 0 ºC -40
    Atmospheric pressure: 86kPa-104kPa

12. Dimension (L ×W×H):310×230×90mm

13. Weight :About2-3Kg

Principle

The Block diagram of the apparatus is shown as Figure 1

1. Constant current source control circuit,
   This part of the circuit is shown as Figure 2, positive Vbe of transistor is offset due to the closed-loop of integrated circuits， if it is ignored as block offset voltage  IUP=IDOWN=VC/R

2. Square-wave generator,
   This is a constant current source controlled with triangular wave – square- wave generator, in Figure 3. Diode consisted circuit control capacitor C charging and  discharging, using high-speed comparator to control the on and off of the diode switches (V105-V111). When the comparator B is high, V107 and V109 conduct，V105  and V111 cut-off, constant current source doing positive charge to integral capacitance C, when the comparator B is low, V105 and V111 conduct，V107 and  V109 cut-off, constant current source doing positive discharge to integral capacitance C .So as the cycle, the output of a point is the triangle wave, the output of B points is the square wave.
   While wave, square wave change, you could also change the integral capacitance to change the frequency of equipment.

PA (Power Amplifiers)
In order to guarantee a very high slew rate and good stability, power amplifier circuit used as the dual-channel, the entire amplifier circuit has the inverted phase features.

Digital frequency meter
The circuit is made up of broadband amplifier, square-wave shaper, microcontroller, LED display, etc. When the frequency is working at the “External measurement” state,  the external signal was sent to counter to count after amplifying and regulation, finally displayed on the LED digital tube.
While internal measurement, the signal entered into the counter directly, counting the time of gates, LED tube decimal point location and Hz or KHz are determined by the CPU.

Power
This instrument use three groups of±23，±17，±5 powers。 The ±17 is the main regulation power supply; ±5 is obtained by three-regulator integrated circuits 7805 for  the use of frequency, ±23 used as power amplifier.

Structural Features

The instrument adopts the all-metal chassis with solid structure, pasted plastic panels, new beautiful appearance。And it is small with light weight, the majority components （Including the key switch） of the circuit are installed on a printed circuit board。 All the adjustment components are placed on the apparent position. When the equipment needs to be repaired, you can remove the two fastening screws of the back plate, to unload the upper and lower plate.

Instruction of use and maintenance

1. Panel sign and Function Description; See as table 1 and Figure 6
   

Panel sign and function Description

apparatus is on working condition
2| I unction| Waveform choice| I) selection of output waveform
2) Coordinate with the SYM, INV, you
could get the positive and negative sawtooth wave and pulse wave
3| R an ge| Frequency-selective switch| Frequency-selective switch and”8″ choose the working frequency
4| Hz| frequency units| indicate frequency units, lighting as
effective
5| KHz| frequency units| frequency units, lighting as effective
6| Gate| gate show| While lighting it means that frequency meter is working.
7| | digital LED| All the internally generated frequency or the outside measured frequency is displayed by the six LED.
8| FREQ| Frequency regulation| inner and outer measuring frequency
(press) signal tuner
---|---|---|---
9| EXT-20dB| External input frequency attenuation 20dB coordinates with 3 select working frequencies.| Outer measuring frequency attenuation
selection, while pressing the signal
attenuated 20dB
10| CORNTER| Counter input| While measuring the outside frequency ,the signal entered from here
I I| PULL.SYW| Ramp, pulse wave of the knob adjustment knob| Pulled out the knob, you can change the symmetry of output waveform, resulting in ramp and pulse with adjustable duty cycle, this knob is promoted as symmetrical waveform
I 2| VCR IN| VCR input| External voltage control the frequency of input
13| PULL DC
OFFSET| DC bias adjustment knob| Pulled out the knob, you can set the DC Operating Point of any waveform, Clockwise direction is positive ,
Anti-clockwise for negative, this knob is
promoted then the DC-bit is zero.
14| TTUCMOS OUT| TTIJCMOS output| The output waveform as the TTL / CMOS pulse can be used as synchronous signals
---|---|---|---
15| PULL TO
TTL CMOS LEVEL| TTL,CMOS Regulation| Pulled out the knob, you could get TTL pulse
It is promoted CMOS pulse and its range could be adjusted
16| OUT PUT| signal output| The output waveform is output from here. The impedance is 5012
17| ATTENUA TOR| output attenuation| Press the button and it could
generate attenuation of -20dB
or-40dB
18| PULL AMPL/INV| Oblique wave inversion
switch, the rate adjustment knob| I. Coordinate with “11”, when
pulled out the wave is reverse. 2.Adjust the size of the output range
19| FINE| Frequency adjust slight| Coordinate with ” ( 8 ) ” , used to
adjust smaller frequency
20| OVFL| Overflow display| When frequency is overflow , the
instrument display.

Maintenance and calibration.
The apparatus could work continuously under the required conditions, but in order to guarantee good performance, we proposed to correct every three months. The order of correction is as follows:

1. Adjustment of sine wave distortion
   Symmetry, the DC bias and modulation control switch are not pulled out, placed the frequency multiplier to “1K”, the frequency display as 5Khz or 2KHz, slowly adjust  the potentiometer RP105, RP112, RP113 so that the distortion is minimum, repeat the above work several times ,sometimes the whole band (100Hz- 100KHz) is less  than 1% distortion

2. Square-wave
   Operating frequency to 1MHz, correct C174 so that the square-wave response is at the best moment

3. Frequency accuracy adjustment Set the frequency meter as “EXT” state; connect the standard signal source 20MHz output to
   external counter, adjust C214 to display as 20000.0 KHz.

4. Frequency sensitivity adjustment
   The sine-wave signal which the output range of signal source is 100mVrms and frequency is 20MHz is connected to external counter, the gate time is set to0.01s; adjust  RP115 to display as 20000.0 KHz

Trouble clearing
Trouble clearing should be doing under the condition of you are familiar with the working principle and circuit. You should inspect the circuit step by step as the following  order: the regulated power supply – Triangle wave – square wave generator – sine wave circuit – power amplifier frequency count circuit – the display part of frequency meter.  You should replace the integrated circuit or other components while founding which part is in trouble.

Preparation of Annex

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