Electrical Specifications
PUSH
TO
TEST
S1
SWITCH TO TEST IN
EACH DIRECTION
VBO
V
BO
IPK
TRACE STOPS
VBO
100-250
VAC
60 Hz
I
100-250
VAC
60 Hz
100
Ω
1%
DEVICE
UNDER
TEST
H
LOAD
IH
120-145
CONDUCTION
ANGLE
IH
IH
S1
SCOPE
SCOPE INDICATIONS
˚
LOAD CURRENT
Figure 9.14 Dynamic Holding Current Test Circuit for Sidacs
Figure 9.15 Basic Sidac Circuit
(a) Circuit
VBO
R
SIDAC
VDC(IN)
≥
VB0
VC
t
RL
IL
VC
(b) Waveforms
C
IL
Rmax
≤
Rmin
≥
VIN - VBO
IBO
VIN - VTM
IH
(MIN)
t
Figure 9.16 Relaxation oscillator Using a Sidac
VCE MONITOR
(See Note B)
RBB1 =
150Ω
100 mH
TIP-47
INPUT
VOLTAGE
0V
5V
COLLECTOR
CURRENT
0.63 A
0
tw
≈
3 ms
(See Note A)
tw
100 mS
INPUT
2N6127
(or equivalent)
50Ω
50Ω
R
BB2 =
100Ω
+ VBB2 =0
+
VCC = 20 V
-
IC MONITOR
SIDAC VBO
COLLECTOR
VOLTAGE
10 V
VCE(sat)
R = 0.1
Ω
S
VBB1 =10 V
-
TEST CIRCUIT
VOLTAGE AND CURRENT WAVEFORMS
NOTE A: Input pulse width is increased until ICM = 0.63A.
NOTE B: Sidac (or Diac or series of Diacs) chosen so that VBO is just below VCEO rating of transistor to be protected.
The Sidac (or Diac) eliminates a reverse breakdown of the transistor in inductive switching circuits where otherwise the
transistor could be destroyed.
Figure 9.17 Sidac Added to Protect Transistor for Typical Transistor Inductive Load Switching Requirements
SIDAC
9-6
Teccor Electronics
(972) 580-7777