CA3059 Intersil, CA3059 Datasheet - Page 21

• Manufacturer Part Number: CA3059
• Description: ZERO VOLTAGE CROSSING SWITCH
• Manufacturer: Intersil

Specifications of CA3059

• Rohs Status: RoHS non-compliant

output under DC operation should be limited to 20mA. The
motor triac is synchronized to zero crossing because it is a
high current inductive load and there is a change of generat-
ing RFI. The solenoid is a very low current inductive load, so
there would be little chance of generating RFI; therefore, the
initial triac turn-on can be random which simplifies the
circuitry.
This example shows the versatility and advantages of the
Intersil zero-voltage switch used in conjunction with triacs as
interfacing and control elements for machine control.
FIGURE 44. TIMING DIAGRAM FOR SOLID-STATE MACHINE
FIGURE 45. SCHEMATIC OF PROPOSED SOLID-STATE MA-
500
REVOLUTION
PULSE 60Hz
TIME DELAY
FUNCTION
OR ONE-
SHOT
MULTI-
VIBRATOR
OPERATION
CROSSING
SOLENOID
MACHINE RATE
SWITCHING
MACHINE
MOTOR
500
ZERO-
ZERO
500
PULSE
SYNC
RATE
ONE
4K
CONTROL
LENGTH
CHINE CONTROL
PULSE
10K
ADJ.
5K
50K
10K
+6 V
10
+6V
10ms
+6V
10K
3K
8.3ms
13
8
10ms
7
13
9
8
7
8
7
ZVS
2
9
2
0.1
ZVS
ZVS
5K
12
10K
2
9
10
1M
11
5
13
12
REP RATE
MACHINE
1
500
10K
4
+6V
4
4
+6V
500
MOTOR CONTROL
500
5K
Application Note 6182
+6V
250
SOLENOID
MACHINE
REP RATE
CROSSING
INVERTED
60
PULSE
ZERO-
MOTOR
M
+V
0
VAC
120
+V
0
21
400Hz Triac Applications
The increased complexity of aircraft control systems, and the
need for greater reliability than electromechanical switching
can offer, has led to the use of solid-state power switching in
aircraft. Because 400Hz power is used almost universally in
aircraft systems, Intersil offers a complete line of triacs rated
for 400Hz applications. Use of the Intersil zero-voltage
switch in conjunction with these 400Hz triacs results in a
minimum of RFI, which is especially important in aircraft.
Areas of application for 400Hz triacs in aircraft include:
1. Heater controls for food warming ovens and windshield
2. Lighting controls for instrument panels and cabin illumination
3. Motor controls and solenoid controls
4. Power supply switches
Lamp dimming is a simple triac application that demonstrates
an advantage of 400Hz power over 60Hz power. Figure 46
shows the adjustment of lamp intensity by phase control of the
60Hz line voltage. RFI is generated by the step functions of
power each half cycle, requiring extensive filtering. Figure 47
shows a means of controlling power to the lamp by the zero-
voltage switching technique. Use of 400Hz power makes possi-
ble the elimination of complete or half cycles within a period
(typically 17.5ms) without noticeable flicker. Fourteen different
levels of lamp intensity can be obtained in this manner. A line
synced ramp is set up with the desired period and applied to
terminal No. 9 of the differential amplifier within the zero-voltage
switch, as shown in Figure 48. The other side of the differential
amplifier (terminal No. 13) uses a variable reference level, set
by the 50K potentiometer. A change of the potentiometer set-
ting changes the lamp intensity.
FIGURE 46. WAVEFORMS FOR 60Hz PHASE CONTROLLED
FIGURE 47. WAVEFORMS FOR 400Hz ZERO-VOLTAGE
60Hz LINE
400Hz LINE
VOLTAGE
defrosters
OUTPUT
VOLTAGE
OUTPUT
SYNCED
LAMP
LAMP
RAMP
LINE
LAMP DIMMER
SWITCHED LAMP DIMMER
16.67ms
17.5ms
REFERENCE
VARIABLE
LEVELS