K0900E70 Datasheet, PDF (137/224 Pages) Teccor Electronics – Thyristor Product Catalog

Application Notes
AN1003
UJT Triggering Level
Pedestal
UJT Emitter Voltage
Cool
Hot
Load
Ramp
0
Time
D1 D2
R1
120 V
(60 Hz)
D3 D4
R2
R3
D5
R5
Temp
R4 ^T
R6 _"Gain"
R7
D6
C1
R8
Q1
T1
Q2
Triac
R1, R2 = 2.2 k, 2 W
R3 = 2.2 k, 1/2 W
R4 = Thermistor, approx. 5 k
at operating temperature
R5 = 10 k Potentiometer
R6 = 5 M Potentiometer
R7 = 100 k, 1/2 W
R8 = 1 k, 1/2 W
Q1 = 2N2646
Q2 = Q2010L5
T1 = Dale PT 10-101
or equivalent
D1-4 = 200 V Diode
D5 = 20 V Zener
D6 = 100 V Diode
C1 = 0.1 µF, 30 V
Figure AN1003.13 Precision Proportional Temperature Control
Several speed control and light dimming (phase) control circuits
have been presented that give details for a complete 120 V appli-
cation circuit but none for 240 V. Figure AN1003.14 and Figure
AN1003.15 show some standard phase control circuits for 240 V,
60 Hz/50 Hz operation along with 120 V values for comparison.
Even though there is very little difference, there are a few key
things that must be remembered. First, capacitors and triacs con-
nected across the 240 V line must be rated at 400 V. Secondly,
the potentiometer (variable resistor) value must change consider-
ably to obtain the proper timing or triggering for 180° in each half-
cycle.
Figure AN1003.14 shows a simple single-time-constant light dim-
mer (phase control) circuit, giving values for both 120 V and
240 V operation.
L1
Load
C1
R2
3.3 k
R3 *
100
AC
R1
Q1
Input
D1
C2
0.1 µF HT-32
C3 *
100 V
Note: L1 and C1 form an
RFI filter that may be eliminated
* dv/dt snubber network
when required
AC
AC
Input Load
Voltage Current ^R1
C1, C3
L1
Q1
120 V ac 12 A
60 Hz
240 V ac 3 A
50/60 Hz
250 k
500 k
0.1 µF 200 V 100 µH Q2015L9
0.1 µF 400 V 200 µH Q4004L4
Figure AN1003.14 Single-time-constant Circuit for Incandescent Light
Dimming, Heat Control, and Motor Speed Control
The circuit shown in Figure AN1003.15 is a double-time-constant
circuit which has improved performance compared to the circuit
shown in Figure AN1003.14. This circuit uses an additional RC
network to extend the phase angle so that the triac can be trig-
gered at small conduction angles. The additional RC network
also minimizes any hysteresis effect explained and illustrated in
Figure AN1003.10 and Figure AN1003.11.
Load
AC
Input
C1
L1
R1
3.3 k
R3
R2
15 k
1/2 W
C2
C3
0.1 µF
100 V
Note: L1 and C1 form an
RFI filter that may be eliminated
R4 *
Q1
100
D1
HT-32
C4 *
* dv/dt snubber network
when required
AC
AC
Input Load
Voltage Current R2
120 V ac 8 A
60 Hz
250 k
240 V ac 6 A
50 Hz
500 k
240 V ac 6 A
60 Hz
500 k
C1, C2, C4
L1
Q1
0.1 µF 200 V 100 µH Q2010L5
0.1 µF 400 V 200 µH Q4008L4
0.1 µF 400 V 200 µH Q4008L4
Figure AN1003.15 Double-time-constant Circuit for Incandescent Light
Dimming, Heat Control, and Motor Speed Control
©2002 Teccor Electronics
Thyristor Product Catalog
AN1003 - 5
http://www.teccor.com
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