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Series T-670
High Precision SparkGap SwitchesFor use in:
Laser Drivers Marx Generators
Capacitor Banks
Current Injectors
Pulse-forming Networks
Specifcations
Maximum Peak Current: 100 kA
Voltage Range: 18-100kV
Timing Jitter (RMS): 50% (CV)*
Maximum Charge Transer: 0.15 Coulomb
Maintenance Interval at
Full Ratings: >10,000 Shots
The T-670 switch is an extremely versatile and compact
pressurized spark gap. Designed or operation in the
20 to 100 kV range, the switch can reliably handle a peak
current o 100 kA and a charge transer o 0.15 Cou-
lomb. Its unique pancake design allows maximum use o available
space or high density packaging and
low inductance. The T-670 can be operated maintenance-ree or
more than 10,000 shots at ull ratings,
making it ideally suited or systems requiring a high rate o use
with minimum down-time. This switch has
proven to be the standard o the industry because o its high
reliability, versatility, long lie, low maintenance,and easy
disassembly or periodic cleaning.
General Description
These switches are used in laser drivers, Marx generators,
capacitor banks, current injectors, pulse-orming
networks, and other applications requiring high-voltage
switching. Their pancake confguration makes them
particularly well-suited to airly high-energy applications
requiring small size and/or low inductance.
Applications
*(CV) Charge Voltage
L-3 Communic ations Pulse Sciences 2700 Merced St. San Leandro,
CA 94577-0599 Phone (510) 577-7150 Fax (510) 577-7129
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200
180
160
140
120
100
80
60
40
20
0 10 20 30 40 50
Synthetic
Air
SF 6
0.75 cm total
electrode gap
200
180
160
140
120
100
80
60
40
20
0 10 20 30 40 50
Synthet
icAir
SF 6
1.0 cm total
electrode gap
SELF-BREAK
VOLTAGE
(kV)
SELF-BREAK
VOLTAGE
(kV)
PRESSURE (PSIG) PRESSURE (PSIG)
Typical Installations
Dimensions and MountingGas Inlet and
Discharge .25 "
O.D. Tubing
1/2-20 UNF-2A
Main Electrode
Connection1/4-20 UNC-2A
Trigger Electrode
Connection
4.25 in. 2.5 in.
4.25 in.
Marx Generator Circuit Current Injection PulserTO ADDITIONAL
STAGES
TRIGGERIN
Rt
Rt
Rc
Rc
Rc
Rt
Rc
Rc
Rb
Rc
Rb
C2
C1
RL
Rc
Rt
Rt
-50 kV+50 kV
Components Note:
C1 Energy Discharge Capacitor
C2 Trigger Isolation Capacitor
Rb Trigger Bias Resistor
Rc Charge Current Limiting Resistor
RL Load Resistance
= Charging Resistor,
20 k Typ.
= Trigger Coupling
Resistor 2 k Typ.
Trigger
Pulse In
100 kVDC
- +
Negative charging voltage
produces produces positive
pulse output. Reverse charging
polarity for negative output.
These curves depict the sel-breakdown parameters o the T-670
switches in the two available gap options.
The operating voltage should be approximately 75% o the
sel-breakdown levels. Triggering is accomplished
by applying a voltage to the mid-plane electrode. The trigger
pulse should be a minimum o 50% o the
gap operating voltage - 100% is recommended.
Self-Breakdown Voltage Versus Pressure
T-670/IND/2002/11L-3 Communications Pulse Sciences 2700 Merced
St. San Leandro, CA 94577-0599 Pho ne (510) 577-7150 Fax (510)
577-7129
