beautypg.com

Testing the function generator – Elenco Digital / Analog Trainer Kit Version User Manual

Page 33

background image

VOLTAGE ANALYSIS OF ANALOG SECTION

Proceed with the voltage analysis only if the resistance readings were satisfactory. The values given below
are approximate.
The following measurements will be taken from the copper side of the PC board. Turn the unit on and place it
upside down.
See Figure J for locations of the testing points.

From

To

Circuit

Volts

Volts Measured

Pin 4 (U6)

GND (B1)

U6 Vcc

+12V

Pin 12 (U6)

GND (B1)

U6 GND

–12V

Pin 7 (U10)

GND (B1)

U10 Vcc

+12V

Pin 4 (U10)

GND (B1)

U10 Vcc–

–12V

TESTING THE FUNCTION GENERATOR

Note: Use the knobs when turning the switches.

TESTING THE SINE WAVE

1. Set your meter to the 200mV DC range.

2. Connect the red meter lead to the 4-pin breadblock marked FREQ and the black lead wire to the 4-pin

breadblock marked GND.

3. Set the WAVEFORM knob to SINE, COARSE FREQUENCY knob to 1k and the FINE ADJ and AMPLITUDE

knobs fully clockwise.

4. Set the DC offset to the middle position. Then, turn on the trainer.

Turn unit right side up.

Figure J

-32-

1

2
3
4

5

6
7
8

10

9

11

12

13

14

15

16

1

2
3
4

8

7
6
5

U10

GND

U6

12

4

7

4