The XR-2206 is comprised of four functional blocks, a voltage
controlled oscillator (VCO), an analog multiplier & sine shaper, a
unity gain buffer amplifier and a set of current switches.
The VCO actually produces an output frequency proportional to
an input current. Across pins 5 and 6, two timing capacitor are
switched between to give different frequency ranges. On pin 7,
the 1M
Ω
variable resistor controls the actual frequency output.
These two components form the RC time constants for the
oscillator frequency.
The VCO produces a square wave signal. This square wave is
sent to a shaper and converted into a sine wave.
THE LOGIC INDICATORS
There are eight logic indicators.
Figure 9 shows the circuit.
It consists of a
transistor, LED, and three resistors. The two 18k
Ω
resistors form a voltage divider.
When the input is over 1.4V, the transistor will turn on allowing current to flow
through the LED to ground, thus turning it on. The 150
Ω
resistor limits the current
in the LED to about 30mA.
Figure 9
-9-
WARRANTY POLICY
Your XK-150 Digital / Analog Trainer has been tested and conforms to our rigid requirements on performance and durability. It is
guaranteed to be free of defects in workmanship, materials and construction for a period of 2 years. If this product should fail during
normal use within the first 3 months from the date of purchase, Elenco will repair or replace the unit at no cost. For the remainder of the
warranty period, a nominal service charge is required to cover shipping and handling.
When returning merchandise for repair, please include proof of purchase, a brief letter of explanation of problem and sufficient packing
material. Before returning any merchandise, please call our service department at (847) 541-3800 to obtain a return authorization
number (RA).
Elenco Electronics, Inc. Service Department
150 W. Carpenter Avenue Wheeling, IL 60090
Input
Vcc
150
LED
18k
18k
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
Symmetry
ADJ.
Waveform
ADJ.
Ground
Sync
Output
Bypass
FKS
Input
Timing
Resistor
Timing
Capacitor
V+
Mult. Out
Sine/Saw
Output
AM Input
+1
Multiplier
and
Sine
Shaper
VCO
Current
Switches
Figure 8
Содержание XK-150
Страница 11: ...10 SCHEMATIC DIAGRAM...
